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Background : Acute Achilles tendon rupture (AATR) is a common injury of the foot and ankle. So far, the optimal management of AATR remains controversial. The target of the present retrospective study was to describe a new operative technique for percutaneous repair of AATR and evaluate efficacy of the technique. Methods : In the present study, 32 patients were enrolled with AATR treated with the percutaneous oval forceps suture-guiding method with anchor nails from Jan 2014 to Jan 2017. The operation duration and length of incision were collected. The functional outcomes were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, Achilles tendon total rupture score (ATRS), range of motion (ROM) of the ankle and plantar flexion strength ratio at the last follow-up. The postoperative sports activity level and complications were also recorded. Results : The mean operation duration and length of incision were 24.5 min and 2.0 cm. Whilst patient reported outcome questionnaires like AOFAS and ATRS showed good results, ROM of the ankle was quite low with only 16.5 degrees. Plantar flexion strength ratio was lower post surgery, as well. As for the postoperative sports activity level: 26/32 cases (81.3%) returned to former sports activity level; 4/32 cases (12.5%) showed a decline in sports activity level; 2/32 cases (6.2%) gave up on sports. The overall complication rate was 6.2%, one sural nerve damage and one fusiform thickening were found in the study. Conclusion : The percutaneous oval forceps suture-guiding method with anchor nails is a new considerable surgery method with adequate healing rates and an alternative to existing surgical procedures.

Background: Lower survival rates for many cancer types correlate with changes in nuclear size/scaling in a tumor-type/tissue-specific manner. Hypothesizing that such changes might confer an advantage to tumor cells, we aimed at the identification of commercially available compounds to guide further mechanistic studies. We therefore screened for Food and Drug Administration (FDA)/European Medicines Agency (EMA)-approved compounds that reverse the direction of characteristic tumor nuclear size changes in PC3, HCT116, and H1299 cell lines reflecting, respectively, prostate adenocarcinoma, colonic adenocarcinoma, and small-cell squamous lung cancer. Results: We found distinct, largely nonoverlapping sets of compounds that rectify nuclear size changes for each tumor cell line. Several classes of compounds including, e.g., serotonin uptake inhibitors, cyclo-oxygenase inhibitors, β-adrenergic receptor agonists, and Na +/K + ATPase inhibitors, displayed coherent nuclear size phenotypes focused on a particular cell line or across cell lines and treatment conditions. Several compounds from classes far afield from current chemotherapy regimens were also identified. Seven nuclear size-rectifying compounds selected for further investigation all inhibited cell migration and/or invasion. Conclusions: Our study provides (a) proof of concept that nuclear size might be a valuable target to reduce cell migration/invasion in cancer treatment and (b) the most thorough collection of tool compounds to date reversing nuclear size changes specific to individual cancer-type cell lines. Although these compounds still need to be tested in primary cancer cells, the cell line-specific nuclear size and migration/invasion responses to particular drug classes suggest that cancer type-specific nuclear size rectifiers may help reduce metastatic spread.

Background Percutaneous reduction, cannulated screw fixation and calcium sulfate cement grafting (PR + CSC) for treatment of displaced and intra-articular calcaneal fractures (DIACFs) is a difficult technique, because the minimally invasive treatment has limited exposure and cannot be used to reduce articular surface under direct vision. The goal of this study was to apply 3D printing technology to preoperative planning and surgery of DIACFs, and to evaluate its effectiveness, feasibility and safety in fracture repair. Methods We enrolled 81 patients with DIACFs in the study from August 2015 to August 2017. Patients with DIACFs in our hospital were randomly divided into the 3D printing group (40 cases) and the conventional group (41 cases). The operation duration, blood loss volume and the number of fluoroscopy were compared. Radiological results were evaluated using radiographs and functional results were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score. The complications were also assessed. In addition, we made a questionnaire to verify the usefulness of the 3D printed model for both doctors and patients. Results The operation duration, blood loss volume and the number of fluoroscopy in 3D printing group were significantly less than that in the conventional group. Besides, 3D printing group achieved significantly better radiological results than conventional group both postoperatively and at the final follow-up except the calcaneal width at the final follow-up. The AOFAS score in the 3D printing group was significantly higher than that in the conventional group. In addition, the questionnaire from doctors and patients exhibited high scores of overall satisfaction of the 3D printed models. As for complications, there was no significant difference among the two groups. Conclusion This study suggested the clinical feasibility of PR + CSC assisted by 3D printing technology in the treatment of DIACFs. Level of evidence II.

Rapid manufacturing of functionalized polymers enable a cost-efficient method for many applications in the biological, and medical sector. Laser structuring techniques differ for fast fabrication processes of thermoplastics. Here we report on direct UV laser ablation of polystyrene and polydimethylsiloxane to control wettability and bio-compatibility. For this purpose contact angle measurements and L929 cell growth experiments were performed as function of laser and process parameters. This work also describes the potential of laser-assisted hot embossing which has been introduced to replicate pre-fabricated micro- and nano-sized structures onto polymers proving it to be a cost-efficient and flexible method for surface functionalization. Therefore, pre-fabricated laser-induced periodic surface structures have been manufactured as mould inserts using ultrafast laser radiation near the ablation threshold. These mould inserts can also be made of nickel, silicon or glass proving laser-assisted hot embossing to be a versatile tool for the functionalization of thermoplastics and meet the requirements for modern manufacturing with regard to quality and production flexibility.

Graphite composite electrodes mixed with silicon are proposed as next generation anode material for high energy and high power applications. In order to overcome drawbacks caused by volume changes of silicon particles during electrochemical cycling and to maintain high specific capacities at enhanced C-rates, free-standing structures are generated on silicon/graphite electrodes by applying ultrafast laser ablation. Electrochemical properties are systematically investigated by means of galvanostatic measurements, cyclic voltammetry, and electrochemical impedance spectroscopy. Cells with structured electrodes exhibit improved battery performances and lithium-ion transport kinetics in comparison to cells with unstructured electrodes. Furthermore, the cells with structured electrodes exhibit a lower impedance at fully lithiated state. After cycling, post-mortem analysis is performed revealing that the mechanical stress within the electrodes and current collector can be significantly reduced due to laser generated free-standing structures.

Achilles tendons have a very poor capacity for intrinsic regeneration. The cell-based treatment strategy for Achilles tendinitis includes the application of mesenchymal stem cells (MSCs), which have high proliferative and multipotent differentiation ability, and is a promising approach. The aim of the present study was to explore the tenogenic potential of human menstrual blood stromal stem cells (MenSCs) in a co-culture system and to compare the tenogenic capability under normoxic and hypoxic conditions. MenSCs were co-cultured indirectly with Achilles tendon cells in a Transwell co-culture system for 1, 2, or 3 weeks in two different concentrations of oxygen (20 and 2% O2), whereas the control contained only MenSCs. The extracellular matrix of MenSCs in each system was evaluated by Alcian blue staining assay, histological staining, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and western blot analysis. Alcian blue staining assay revealed a significant increase (P

Laser processing technologies for micro-/nanostructuring of electrode materials have a great potential in improving the electrochemical performance and operational lifetime of lithium-ion cells. Different types of laser structuring were used on different surfaces such as metallic current collectors and thin or thick film electrodes. For thin metallic current collector foils, at anode and cathode sides, the self-organized structuring by laser-induced periodical surface structures and laser interference methods were successfully applied for improving electrode film adhesion and cell impedance. For thin and thick film electrode layers direct laser ablation with structure sizes down to the micrometer range and high aspect ratios were found most powerful in order to create three-dimensional (3D) cell architectures with benefits regarding cell performance and a homogenous wetting of composite electrodes with liquid electrolyte. A huge impact of laser formed 3D batteries regarding capacity retention and cell lifetime at high charging and discharging rates was detected. The impact on diffusion kinetics of laser structured 3D electrodes was studied using classical methods such galvanostatic intermittent titration technique and cyclic voltammetry. A further improvement of 3D battery performance due to an operation in high potential regime and for advanced high energy silicon anode material was achieved by joining of laser structuring and thin-film passivation either of active particles before laser patterning or by passivating of complete 3D electrodes after laser processing. Finally, laser-induced breakdown spectroscopy will be presented as a powerful tool for elemental mapping of entire 2D and 3D electrodes. The impact of 3D architectures on lithium distribution and chemical degradation processes in 2D batteries was investigated and analyzed.

High production costs, restricted process reliability, small energy- and power-density, as well as relatively short operational lifetime are the main issues of lithium-ion batteries (LIBs). LIBs with high-energy and high-power density can be realized by introducing a three-dimensional (3D) battery concept, which offers an improved electrolyte transfer in thick film electrodes and an improved lithium-ion transport kinetic. For developing next generation batteries including the 3D battery concept for large footprint areas, high energy materials such as nickel-enriched Lithium-Nickel-Manganese-Cobalt-Oxide (NMC) for cathodes and silicon-based anodes are introduced. The main drawbacks of these types of active materials regarding commercialization are their rather small lifetime due to enhanced mechanical degradation and their restricted chemical stability during electrochemical cycling. Ultrafast laser processing for establishing an advanced electrode design is flanked by an advanced material design, i.e., thin film passivation of active material for maintaining structural and chemical stability on particle level. Such thin film passivation is realized for anodes and cathodes by carbon- or alumina-coated silicon nanoparticles and LPO(Lithium-Phosphate)-coated NMC, respectively. Cyclic voltammetry is proving the successful combination of laser generated 3D electrode architecture and material concept while galvanostatic measurements reveal that batteries with structured electrodes provide an enhanced capacity retention and an improved lithium-ion diffusion kinetics compared to cells with unstructured electrodes.

In situ scanning electron microscopy (SEM) offers a good way to investigate the structural evolution during lithiation and delithiation processes. In this paper, the dynamical morphological evolution of 3D-line-structured/unstructured Si/C composite electrodes was observed by in situ SEM. The investigation revealed the microstructural origin of large charge capacity for 3D-line-structured anodes. Based on this proposed mechanism, a coarse optimization of 3D-line-structured anodes was proposed. These results shed light on the unique advantages of using an in situ SEM technique when studying realistic bulk batteries and designing 3D electrode structures.

A magnetic photocatalyst Fe3O4@MIL-53(Fe) was successfully obtained from the calcination treatment of pristine MIL-53(Fe) to degrade ibuprofen (IBP) under visible light. The results suggested that Fe3O4 and MIL-53(Fe) co-existed after the calcination of MIL-53(Fe) at 400 ℃ (CM53−400) and pearl-like Fe3O4 nanoparticle intimately combined with MIL-53(Fe) in CM53−400. Fe3O4@MIL-53(Fe) composites exhibited superior photocatalytic performance due to the unique structure and electron transfer between Fe3O4 and MIL-53(Fe). CM53−400 processed the best catalytic ability for IBP degradation, achieving 99 % removal of IBP in the presence of H2O2 within 60 min. The improved photocatalytic activity of CM53−400 may originate from the enhanced photoexcited electron-hole pairs separation. The active species, h+, OH, e− and O 2−, played important roles in the photo-degradation processes. In addition, due to the stable activity of CM53−400 toward IBP decomposition and the strong magnetism of CM53−400 composite, CM53−400 photocatalysts bring new insights into the practical application for removing the organic contaminants from water.

Laser structuring of battery materials such as electrodes, current collectors, and separator materials becomes more and more a versatile tool for a flexible designing of battery performance with regard to high rate capability, reduced impedance and diffusion over-potential, enhanced battery lifetime, and a tremendous improvement of electrode wetting with liquid electrolyte. Especially structuring of thick film composite electrodes with film thickness up to 300 µm is of great interest for combining high energy and high power applications. Laser ablation by using ultrafast laser radiation ensures a high aspect ratio structuring without damaging or modifying the material properties of the active material, inactive compounds, and current collector. Thermal induced material modification and laser-induced material splatter on top of the electrode surfaces have been so far a major problem by using conventional nanosecond lasers. However, in recent years high power OEM-type ultrafast laser beam sources became available for industrial production. Those lasers provide powers of several 100 W up to the kW-regime with repetition rates of several tenfold MHz, which makes high-speed parallel material processing feasible. Finally, after introducing high-speed nanosecond laser cutting of electrodes almost one decade ago, we forecast that with regard to recent technical approaches quite soon high-speed electrode ultrafast laser structuring will entering the pilot line level. For this purpose, at KIT, parallel processing of cathode and anode materials with large foot print area is being developed in a roll-to-roll (R2R) environment in order to meet the process speed requirements of cell production. Furthermore, we are developing thick film electrode concepts for anodes made of graphite and silicon-graphite and cathodes based on Lithium-Nickel-Manganese-Cobalt-Oxide (NMC) with varying nickel content and water-based slurries. Electrode thicknesses in the range of 100-300 µm were synthesized for subsequent laser processing, cell assembly, and electrochemical characterization such as galvanostatic measurements, galvanostatic intermittent titration technique, cyclic voltammetry, and electrochemical impedance spectroscopy. Large area laser structuring in R2R environment for generation of three-dimensional (3D) electrode architectures with increased active surface area, enhanced mechanical integrity for high energy materials such as Si-graphite anodes and an overall boost in electrochemical performances on pouch cell level will be presented. Laser-induced breakdown spectroscopy (LIBS) was applied for elemental mapping of entire electrodes in order to characterize binder migration in ultra-thick film electrodes, and in post-mortem studies to evaluate degradation processes in unstructured, damaged, and structured thick film electrodes with large footprint (pouch cell level). Post-mortem studies show that significant chemical modifications across from electrodes with macroscopic surface defects could be detected while laser structured electrodes provide less inhomogeneity in lithium distribution in comparison to cells with unstructured electrodes. Furthermore, an inhomogeneity in mechanical load on cells could be identified as a main reason for cell degradation. LIBS is presented as a perfect tool to rapidly characterize and identify starting points for cell degradation on coin cell and pouch cell level. In summary, ultrafast laser structuring of electrodes provides a new manufacturing tool for next generation battery production to overcome current limitations in electrode design and cell performances.

Due to the excellent theoretical capacity, silicon-based electrodes have been extensively studied to develop high energy-density lithium-ion batteries (LIBs). Nevertheless, the large volume expansion and unfavorable interface seriously hamper its application, and the underlying physics behind are still unclear. In this work, using in-situ environment scanning electron microscopy (ESEM), the morphological evolution of composite silicon-graphite electrodes with different ionic liquids as electrolytes are compared in the range of 20 °C–60 °C. Surprisingly, combining the microstructure and surface reaction products from transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS), it finds out that the fully reaction of lithium-silicon does not generate huge volume expansion, while the side reaction between graphite and electrolyte decomposition products causes dramatic volume expansion and hinders the further lithiation of silicon. On the other hand, the electrolyte which is capable of rapidly releasing F− to form LiF-rich solid electrolyte interphase (SEI) is favorable to maintain the structure integrity and cycling performance. This work casts new understanding from the perspective of intrinsic reaction between electrode and ionic liquid electrolyte, which suggests that the practical application of silicon-based electrodes with appropriate electrolyte is a promising route for high energy-density LIBs.

The electrochemical performance of vanadium redox flow batteries (VRFBs) was enhanced via laser-patterned graphite felt (GF) electrodes. The laser-structured GF electrodes engineered via preparing a series of well-ordered microscopic channel structures with an average width of 200 μm, creating a three-dimensional carbon framework. The ultrafast laser patterning increased the porosity by 10%, as compared to pristine electrode. The analysis of the overpotential distribution using electrochemical impedance spectroscopy revealed that the electrode polarization involving charge transfer and diffusion resistance is strongly alleviated with the aid of carbon micro-perforation. The advanced design of laser-structured GF electrode also exhibits high rate capability, low internal resistance, and excellent cyclability. The improved performance was attributed to the synergistic effect involving (i) high electrochemically active surface area for rapid electrochemical reactions (i.e., V(II)/V(III) and V(IV)/V(V) redox couples) and (ii) excellent transport properties for facile electron/ion/species transport. The micro-scale channels created with the laser-ablation technique act as capillary structures and enabled homogeneous and rapid wetting of GF electrodes as formulated with the classical Washburn equation. The VRFB equipped with the laser-structured GF electrodes delivered a high discharge capacity with exceptional capacity retention upon extended cycling (>84.9%). Accordingly, the design of laser-structured electrode paves the pathway towards finely tuning the electrode internal microstructure for improved cyclability, durability, and capacity retention in various electrochemical energy storage/conversion devices (e.g. all-vanadium redox flow batteries).

Glucocorticoids have been widely used as anti-inflammatory therapies. The mechanisms of cortisol action in goat does with endometritis, however, have not been reported. The aim of this study was to investigate the mechanism of cortisol in modulation of effects of E. coli-induced endometritis in the does. Does (n = 24) were assigned to four groups (n = 6): control, E. coli, cortisol, and E. coli + cortisol groups. Does in the cortisol and E. coli + cortisol group were treated with cortisol from 3 days before E. coli inoculations occurred to 36 days post-partum. Does in the E. coli and inoculation groups were administered via intrauterine infusion E. coli O55 (109 CFU/mL) at 0 h. Physical indicators, macroscopic and microscopic changes in the endometrium, uterine secretion cytology and bacteriology were evaluated before (0 h) and at 6, 12, 24, 48, and 72 h after E. coli inoculation. The TLR4 and pro-inflammatory cytokine mRNA transcripts were detected using qPCR. The activations of NF-κB and MAPK signaling pathways were detected using Western blot procedures. As a result, cortisol inhibited the inflammatory response of does by reducing the clinical symptoms, morphological endometrial damage, % PMN in uterine secretions, relative abundance of inflammatory gene mRNA transcripts in the endometrium of does. Cortisol inhibited NF-κB activity by reducing MyD88 and IκB phosphorylation. Treatment with cortisol suppressed the phosphorylation of ERK1/2, p38MAPK, and JNK. These results indicate the anti-inflammatory effect of cortisol in the endometrium of does may be regulated by NF-κB and MAPK pathways.

The main goal is to develop an optimized three-dimensional (3D) cell design with improved electrochemical properties, which can be correlated to a characteristic lithium distribution along 3D micro-structures at different State-of-Health (SoH). 3D elemental mapping was applied for characterizing the whole electrode as function of SoH. It was demonstrated that fs-laser generated 3D architectures improves the battery performance regarding battery power and lifetime. It was quantitatively shown by laser-induced breakdown spectroscopy that 3D architectures act as attractor for lithium-ions. Furthermore, lateral intrinsic porosity variations were identified to be possible starting points for lithium plating and subsequent cell degradation. Results achieved from post-mortem studies of cells with laser structured electrodes (intrinsic and artificial porosity variation), and unstructured lithium-nickel-manganese-cobalt-oxide electrodes will be presented.

This chapter reviews the use of laser-based material processing techniques, such as pulsed laser deposition (PLD), laser-induced forward transfer (LIFT), and material processing via three-dimentional laser structuring (LS) and laser annealing (LA) techniques for energy storage applications. It also reviews the recent work using these laser processing techniques for the fabrication of micropower sources and lessons learned from the characterization of their electrochemical properties. The chapter shows that laser processing techniques are ideally suited to prototype and fabricate these types of electrochemical energy storage components for hybrid micropower systems. It discusses PLD techniques for thin-film microbatteries, LIFT techniques for ultracapacitors and thick-film microbatteries, LA for controlling the grain size and crystalline phase of thin-film electrodes, and LS processes for modifying active electrode materials for Lithium ion microbatteries. The chapter concludes with a discussion of challenges and future directions offered by the use of lasers to develop the next generation of microbatteries.

The recycling of spent lithium-ion batteries has significant potential to benefit our society economically and environmentally as well as preserving raw materials. Although diverse process chains have been applied or under development to recycle batteries, a common, critical issue for battery recycling is the separation of the metallic current collector from the composite film of the electrode. In this study, inspired by the amazing controllable attachment and detachment ability of geckos’ foot-hairs, microscale near-surface architecture is designed on the interface between the current collector and the composite film in lithium-ion batteries, so that it displays controllable and directional adhesion, i.e., enhanced adhesion can be obtained during its lifetime to cope with the substantial volume changes of the composite film upon intercalation and deintercalation, whereas during recycling, the composite layer of the electrode can be easily peeled off from the current collector in a certain direction. This study is the first application of structural adhesives for the development of easy-to-recycle lithium-ion batteries. This technology can also be extended to other electronic products to avoid an ever-growing volume of electronic waste. The fundamental understanding on the interfacial adhesion and delamination mechanisms provides a scientific footing for the realization of next-generation easy-to-recycle electronics.

STUDY DESIGN Human stromal stem cells derived from menstrual blood (MenSCs) and nucleus pulposus (NP) cells were cocultured under normal or low oxygen (O2) condition. OBJECTIVE To assess the differentiation capability of MenSCs toward nucleus pulposus cells under normal or low oxygen condition. SUMMARY OF BACKGROUND DATA Given the proliferative capacity and pluripotentiality of mesenchymal stem cells, mesenchymal stem cells transplantation is thought to be a promising approach to managing intervertebral disc degeneration. METHODS Using coculture plates with 0.4-μm pore size polyethylene terephthalate track-etched inserts, MenSCs and NP cells (1:1 ratio) were cocultured with cell-to-cell contact for 2 weeks in normal (20% O2) or low oxygen tension (2% O2), respectively. Extracellular matrix accumulation was quantified by dimethylmethylene blue assay, histological staining, and quantitative reverse-transcription polymerase chain reaction. Novel characteristic human NP markers cytokeratin-19 (KRT19), carbonic anhydrase XII (CA12), and forkhead box F1 (FoxF1) were also detected by quantitative reverse-transcription polymerase chain reaction. RESULTS The result of quantitative reverse-transcription polymerase chain reaction showed that aggrecan and COL2A1 genes expression was significantly increased in differentiated MenSCs (P < 0.05). There was significantly more COL2A1 gene expression in normoxic group than that in low O2 group (P < 0.05). But no significant difference was observed in aggrecan gene expression between normoxic group and low O2 group. These aforementioned results were also confirmed by histological analysis. We also found that the characteristic NP markers (KRT19, CA12, FoxF1) were significantly upregulated in differentiated MenSCs. Moreover, low O2 tension (2%) further enhanced these genes expression (P < 0.05). CONCLUSION In our study, MenSCs were successfully differentiated into NP-like cells and may become a new source of seed cells for the treatment of intervertebral disc degeneration in the future. LEVEL OF EVIDENCE N/A.

Laser technology in lithium-ion battery (LIB) manufacturing could enable rapid manufacturing, high reliability, and a reduction of production costs. Laser cutting and welding processes for batteries already reached a high industrial readiness level. A new approach which is assigned to laser micro-structuring of battery materials has a huge impact on battery performance and operational lifetime of lithium-ion cells and an up-scaling for industrial production is currently investigated. So far, different types of laser structuring were used on metallic current collectors, separators, and thin or thick film composite electrodes. For thin metallic current collector foils, at anode and cathode sides, self-organized structuring by laser-induced periodical surface structures were successfully applied for improving electrode film adhesion. Direct laser ablation was applied for the generation of capillary structures, which was found to be most powerful in order to transform electrode and separator surfaces to superwicking. Thick film composite electrodes in lithium-ion cells are complex multi-material systems with defined material components, grain sizes, porosities, and pore size distributions in the micrometer and sub-micron range. The development of laser generated electrode architectures became a promising approach to overcome limitations in lithium-ion diffusion kinetics, high inter-electrode ohmic resistances, and mechanical stresses due to high volume changes during battery operation. It was shown, that structure sizes down to 10-30 µm and high aspect ratios enable advanced electrode architectures with huge benefits regarding capacity retention and cell life-time for high power operations during charging/discharging. For laser structured electrodes, the overall impedance was reduced and the diffusion kinetics could be enhanced which was proven by galvanostatic intermittent titration technique, cyclic voltammetry, and electrochemical impedance spectroscopy. Furthermore, the new electrode architecture provides new lithium-ion diffusion pathways, which could be indirectly proven by post-mortem analysis of entire electrodes by laser-induced breakdown spectroscopy (LIBS). It is evident that the increased active surface area provided by laser generated electrode architectures act as an attractor for lithium-ions which finally is responsible for the boost in battery performances. By increasing the cathode film thickness to values significantly larger than 150 μm an increase of the specific capacity or energy density at cell level was achieved. While the energy per area increases with the cathode layer thickness, the power density will in general decrease due to an increasing diffusion overpotential. In addition, the mechanical integrity of the films will decrease with increasing layer thickness and the migration of binders to the electrode surface will occur through altered drying conditions. The mechanical degradation of the cells due to the volume change inherent in the battery process in the electrodes will become more important as the layer thickness increases. Laser structuring of the electrodes can counteract these processes and will also improve the high current capability. Finally, LIBs with high-energy and high-power density can be realized by introducing laser generated electrode architectures (3D battery concept), i.e., at the same time, improved electrolyte transfer in thick film electrodes and improved lithium ion transport kinetics are achieved. For developing next generation batteries including the 3D battery concept for large footprint areas, high energy materials such as nickel-enriched Lithium-Nickel-Manganese-Cobalt-Oxide (NMC) for cathodes and silicon-based anodes are introduced.

Next generation lithium-ion batteries (LIB) with high energy density and high power density have recently become of great interest for electric vehicle and portable devices. With the further upgrade of especially electric vehicles, the next generation LIB with high power and high energy density is urgently required. For this purpose, composite electrode consisting of commercially available graphite active material mixed with silicon nanoparticles is under current development. The main objectives are a significant increase of the practical capacity and energy density of commercial anodes, an overcome of the drawbacks of pure silicon due to large volume changes during electrochemical cycling, and the development of a technology suitable for mass production. In order to reduce the intrinsic mechanical stress of silicon/graphite electrodes and to improve the lithium-ion transport kinetic, free-standing electrode structures were generated by applying ultrafast industrial capable laser material processing. This advanced laser technology is demonstrated to be a flexible and powerful tool for pushing silicon/graphite (Si/C) composite anode materials beyond state of the art electrodes towards application. The electrochemical properties of cells with unstructured and structured electrodes were systematically analyzed by means of cyclic voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. The increased active surface enables a significant improvement of lithium-ion diffusion kinetics. Furthermore, it is expected that the increased active surface will also provide additional artificial porosity for active material expansion, which in turn will reduce the mechanical stress within the electrodes during lithiation or delithiation. In this context, in-situ scanning electron microscopy (SEM) was performed in order to analyze the active material volume changes during charging and discharging. A main engineering challenge was to optimize the electrode architecture such as the pitch distance of free-standing structures regarding an enhanced electrochemical performance and a reduced material loss. Furthermore, an alumina (Al2O3) layer with a thickness of 5 nm, which acts as an artificial SEI, was coated on structured silicon/graphite electrodes by applying Atomic Layer Deposition (ALD). Cyclic voltammetry measurements were subsequently performed in order to investigate the fundamental properties of cells with structured and Al2O3- coated silicon/graphite electrodes. Galvanostatic measurements reveal that the cells with structured electrodes exhibit excellent electrochemical properties, i.e., a significantly improved capacity retention. ALD layers can contribute to further improvement of cycle stability and cell lifetime. In addition, advanced full cells with Lithium Nickel Manganese Cobalt Oxide NMC622 as cathode and Si/C as counter electrode were assembled and the electrochemical data will be presented.

For next generation of high energy lithium-ion batteries, silicon as anode material is of great interest due to its higher specific capacity (3579 mAh/g). However, the volume change during de-/intercalation of lithium-ions can reach values up to 300 % causing particle pulverization, loss of electrical contact and even delimitation of the composite electrode from the current collector. In order to overcome these drawbacks for silicon anodes we are developing new 3D electrode architectures. Laser nano-structuring of the current collectors is developed for improving the electrode adhesion and laser micro-structuring of thick film composite electrodes is applied for generating of freestanding structures. Freestanding structures could be attributed to sustain high volume changes during electrochemical cycling and to improve the capacity retention at high C-rates (> 0.5 C). Thick film composite Si and Si/graphite anode materials with different silicon content were deposited on current collectors by tape-casting. Film adhesion on structured current collectors was investigated by applying the 90° peel-off test. Electrochemical properties of cells with structured and unstructured electrodes were characterized. The impact of 3D electrode architectures regarding cycle stability, capacity retention and cell life-time will be discussed in detail.

Lithium nickel manganese cobalt oxide (Li(Ni1/3Mn1/3Co1/3)O2, NMC) thick film electrodes were manufactured by using the doctor-blade technique (tape-casting). Ultrafast laser-structuring was performed in order to improve the electrochemical performance. For this purpose, three-dimensional (3D) micro-structures such as free standing micropillars were generated in NMC cathodes by using femtosecond laser ablation. Laser-induced breakdown spectroscopy (LIBS) was used for post-mortem investigation of the lithium distribution of unstructured and femtosecond laser-structured NMC electrodes. For achieving a variable State-of-Health (SoH), both types of electrodes were electrochemically cycled. LIBS calibration was performed based on NMC electrodes with defined lithium amount. Those samples were produced by titration technique in a voltage window of 3.0 V - 5.0 V. Elemental mapping and elemental depth-profiling of lithium with a lateral resolution of 100 μm were applied in order to characterize the whole electrode surface. The main goal is to develop an optimized 3D cell design with improved electrochemical properties which can be correlated to a characteristic lithium distribution along 3D micro-structures at different SoH.

Lithium-ion batteries became the most promising types of mobile energy storage devices due to their high gravimetric and volumetric capacity, high cycle life-time, and low self-discharge. Nowadays, the cathode material lithium nickel manganese cobalt oxide (NMC) is one of the most widely used cathode material in commercial lithium-ion batteries due to many advantages such as high energy density (>150 Wh kg-1) on cell level, high power density (650 W kg-1 @ 25 °C and 50 % Depth of Discharge) [1], high specific capacity (163 mAh g-1) [2], high rate capability and good thermal stability in the fully charged state. However, in order to meet the requirements for the increasing demand for rechargeable high energy batteries, nickel-rich NMC electrodes with specific capacities up to 210 mAh g-1 seem to be the next generation cathodes which can reach on cell level desired energy densities higher than 250 Wh kg-1 [3]. Laser-structuring now enables to combine both concepts, high power and high energy lithium-ion batteries. For this purpose, lithium nickel manganese cobalt oxide cathodes were produced via tape casting containing 85-90 wt% of active material with a film thickness of 50-260 μm. The specific capacities were measured using galvanostatic measurements for different types of NMC with varying nickel, manganese and cobalt content at different charging/discharging currents ("C-rates"). An improved lithium-ion diffusion kinetics due to an increased active surface area could be achieved by laser-assisted generating of three dimensional architectures. Cells with unstructured and structured cathodes were compared. Ultrafast laser ablation was used in order to avoid a thermal impact to the material. It was shown that laser structuring of electrode materials leads to a significant improvement in electrochemical performance, especially at high charging and discharging C-rates.

NMC thick films were prepared by tape-casting and subsequent ultrafast laser-structuring. The lithium distribution in electrochemically cycled and unstructured or fs laser-structured NMC cathodes was investigated by using Laser-Induced Breakdown Spectroscopy (LIBS). The main goal is to develop an optimized three dimensional cell architecture with improved electrochemical properties based on studies of the homogeneity of the local State-of-Charge. LIBS experiments were carried out using a LIBS workstation equipped with a mode-locked diode pumped solid state Nd:YAG laser operating at a wavelength of 1063 nm. The element distribution was investigated using two different techniques: element mapping and element depth-profiling of the unstructured / fs laser-structured electrode surface. Results achieved from post-mortem studies using LIBS will be presented.

Sequential adsorption of water and organic vapor mixtures onto single-walled carbon nanotube (SWNT) bundles is studied experimentally and by grand canonical Monte Carlo (GCMC) simulation to elucidate the distinct interactions between select adsorbates and the nanoporous structure of SWNTs. Experimental adsorption isotherms on SWNT bundles for hexane, methyl ethyl ketone, cyclohexane, and toluene individually mixed in carrier gases that were nearly saturated with water vapor are compared with the GCMC-simulated isotherms for hexane, as a representative organic, on the external surface of the heterogeneous SWNT bundles. From the nearly perfect overlap between the experimental and simulated isotherms, it is concluded that until near saturation only the internal pore volume of pristine SWNT bundles fills with water. The adsorption of water vapor on the peripheral surface of the bundles remains insignificant, if not negligible, in comparison to the adsorption of water in the internal volume of the bundles. This is in contrast with the adsorption of pure hexane, which exhibits appreciable adsorption both inside the bundles and on their external surface. It is also suggested that during competitive adsorption, water molecules take precedence over small nonpolar and polar organic molecules for adsorption inside SWNTs and leave unoccupied the hydrophobic external surface of the bundles for other more compatible adsorbates.

We are reporting gravimetric measurements of adsorption isotherms and kinetics of water vapor in single-walled carbon nanotubes (SWNTs). Adsorption was facilitated in an open configuration. Adsorption capacities of SWNTs were found to be approximately one-half of those of activated carbon and activated carbon fiber. The water adsorption isotherms of SWNTs followed type V characteristics, which are typical for a surface chemistry mediated adsorption of water. The isotherm models, the Dubinin−Serpinski equation and the Do equation, were fitted to the SWNT isotherms. The information about the SWNT surface chemistry could be extracted from data fitting to these equations and was found to be consistent with the same observed from Raman scattering of the SWNTs. The adsorption and desorption rate constants were calculated for all SWNT samples as a function of relative pressure using the linear-driving force model commonly used for activated carbons. The rate constants for both carbon types were in the general ra...

Laser processes for cutting, modification and structuring of energy storage materials such as electrodes, separator materials and current collectors have a great potential in order to minimize the fabrication costs and to increase the performance and operational lifetime of high power lithium-ion-batteries applicable for stand-alone electric energy storage devices and electric vehicles. Laser direct patterning of battery materials enable a rather new technical approach in order to adjust 3D surface architectures and porosity of composite electrode materials such as LiCoO2, LiMn2O4, LiFePO4, Li(NiMnCo)O2, and Silicon. The architecture design, the increase of active surface area, and the porosity of electrodes or separator layers can be controlled by laser processes and it was shown that a huge impact on electrolyte wetting, lithium-ion diffusion kinetics, cell life-time and cycling stability can be achieved. In general, the ultrafast laser processing can be used for precise surface texturing of battery materials. Nevertheless, regarding cost-efficient production also nanosecond laser material processing can be successfully applied for selected types of energy storage materials. A new concept for an advanced battery manufacturing including laser materials processing is presented. For developing an optimized 3D architecture for high power composite thick film electrodes electrochemical analytics and post mortem analytics using laser-induced breakdown spectroscopy were performed. Based on mapping of lithium in composite electrodes, an analytical approach for studying chemical degradation in structured and unstructured lithium-ion batteries will be presented.

A practical approach for adsorption modeling of heterogeneity of single-walled carbon nanotube (SWNT) bundles has been developed. The method integrates experimental analysis with grand canonical Monte Carlo (GCMC) simulation of a small probe molecule, such as nitrogen at 77 K. Using this method, it is possible for one to separately estimate adsorption inside the nanotubes, adsorption on the external surface of the bundles, and adsorptive contributions from the impurities present in samples. By introducing a scaling parameter for adsorption in the internal porous volume of the bundles, the predicted adsorption isotherm results in a near replication of the experimental N2 adsorption isotherm. We refer to this parameter as the volume fraction of open-ended nanotubes. Our GCMC-assisted experimental characterization method has been applied successfully to several commercial samples obtained from different suppliers, such as MER Corp., Carbon Nanotechnologies Inc., Carbon Solutions Inc., Carbolex Inc., and Buck...

Acoustic droplet ejection (ADE) technology uses focused acoustic energy to transfer nanoliter-scale liquid droplets with high precision and accuracy. This noncontact, tipless, low-volume dispensing technology minimizes the possibility of cross-contamination and potentially reduces the costs of reagents and consumables. To date, acoustic dispensers have mainly been used in screening libraries of compounds. In this paper, we describe the first application of this powerful technology to the rapidly developing field of synthetic biology, for DNA synthesis and assembly at the nanoliter scale using a Labcyte Echo 550 acoustic dispenser. We were able to successfully downscale PCRs and the popular one-pot DNA assembly methods, Golden Gate and Gibson assemblies, from the microliter to the nanoliter scale with high assembly efficiency, which effectively cut the reagent cost by 20- to 100-fold. We envision that acoustic dispensing will become an instrumental technology in synthetic biology, in particular in the era of DNA foundries.

It is a routine task in metabolic engineering to introduce multicomponent pathways into a heterologous host for production of metabolites. However, this process sometimes may take weeks to months due to the lack of standardized genetic tools. Here, we present a method for the design and construction of biological parts based on the native genes and regulatory elements in Saccharomyces cerevisiae. We have developed highly efficient protocols (termed YeastFab Assembly) to synthesize these genetic elements as standardized biological parts, which can be used to assemble transcriptional units in a single-tube reaction. In addition, standardized characterization assays are developed using reporter constructs to calibrate the function of promoters. Furthermore, the assembled transcription units can be either assayed individually or applied to construct multi-gene metabolic pathways, which targets a genomic locus or a receiving plasmid effectively, through a simple in vitro reaction. Finally, using β-carotene biosynthesis pathway as an example, we demonstrate that our method allows us not only to construct and test a metabolic pathway in several days, but also to optimize the production through combinatorial assembly of a pathway using hundreds of regulatory biological parts.

The formation of laser-induced periodic surface structures (LIPSS) on metallic surfaces by femtosecond laser radiation was investigated. Various types of LIPSS could be formed on metallic surfaces such as copper and stainless steel. Nano-ripple formation was investigated as function of laser scanning speed, laser pulse number, and laser fluence. Hierarchical structures were generated on stainless steel surfaces and hydrophobic properties with water contact angles of about 145° could be achieved. It could be shown that direct femtosecond laser surface processing is a perfect tool for designing surface properties on micro- and nanometer scale which can be used for optical, biomedical, and tribological applications.

Insufficient energy density is one of the barriers for widespread application of lithium-ion batteries (LIBs). Increasing energy density relies on developing novel active materials with higher energy density and/or increasing the active material ratio via electrode engineering [1]. One natural strategy is to increase the energy density by increasing the electrode thickness, which reduces the fraction of some inactive components such as current collectors and separators. However, thick electrodes suffer from electrolyte depletion under high discharge rates and low power density. As a result, electrodes are divided into two categories—thin electrodes (ca. 50 µm) for high power application and thick electrode (> 100 µm) for high energy application [2]. This work reports a design in thick electrodes with 3D micro-structures enabled by laser processing, which minimizes the electrode tortuosity and improves the lithium ion diffusion kinetics. This novel design enables high energy and high power densities for LIBs. References: [1] Z. Du, D.L. Wood, C. Daniel, S. Kalnaus, J. Li, Journal of Applied Electrochemistry 47 (3), (2017) 405-415 [2] P. Smyrek, J. Proll, H. J. Seifert, and W. Pfleging, Journal of the Electrochemical Society, 163 (2), (2016) A19-26. Acknowledgements This research at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) under contract DE-AC05-00OR22725, was sponsored by the Office of Energy Efficiency and Renewable Energy (EERE) Vehicle Technologies Office(VTO) (Deputy Director: David Howell) Applied Battery Research subprogram (Program Manager: Peter Faguy). This work at Karlsruhe Institute of Technology (KIT) received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 644971. Finally, the support for laser materials processing by the Karlsruhe Nano Micro Facility (KNMF, http://www.knmf.kit.edu/) a Helmholtz research infrastructure at KIT is gratefully acknowledged.