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An improved semi-physical model for a SiC MOSFET incorporated with relevant physical effects and temperature characteristics is proposed based on the EKV model. A simulation analysis of the Junction Field Effect Transistor (JFET) effect, Drain Induced Barrier Lowering (DIBL) effect, channel length modulation effect, velocity saturation effect, and interface trap charge effect in SiC MOSFET devices is performed using Sentaurus TCAD. Based on the influence of physical effects on the characteristics of SiC MOSFET devices, mathematical corrections r(Vgs) and r(Vds), which can describe the relevant physical effects, are introduced into the original EKV model. The capacitance is accurately modelled to achieve the required match between the transient characteristics of the devices. The accuracy of the model is verified by static tests and double-pulse experiments. Results show that the improved model can do a better job of simulating the actual operating conditions of the device. In addition, its accuracy and applicability are greatly improved, providing a semi-physical model with a wider range of applicability for the simulation of SiC MOSFETs in power electronic systems.

Thermal management of flexible/stretchable electronics has been a crucial issue. Mass supernumerary thermal heat is created in the repetitive course of deformation because of the large nanocontact resistance between electric conductive fillers, as well as the interfacial resistance between fillers and the polymer matrix. Here, we report a stretchable thermoplastic polyurethane (TPU)-boron nitride nanosheet (BNNS) composite film with a high in-plane thermal conductivity based on an air/water interfacial (AWI) assembly method. In addition to rigid devices, it was capable for thermal management of flexible electronics. During more than 2000 cycles of the bending–releasing process, the average saturated surface temperature of the flexible conductor covered with composite film with 30 wt % BNNSs was approximately 40.8 ± 1 °C (10.5 °C lower than that with pure TPU). Moreover, the thermal dissipating property of the composite under stretching was measured. All the results prove that this TPU-BNNS composite film is a candidate for thermal management of next-generation flexible/stretchable electronics with high power density.

Polymer semiconductors have been widely studied as an important component of stretchable electronic devices. However, most stretchable polymer semiconductors suffer from different degrees of charge mobility degradation at high strain. Here, we report a novel side chain engineering strategy to realize stretch-induced enhancement of molecular orientation and charge transport in donor–acceptor conjugated polymers. Specifically, hybrid siloxane-based side chains wifth different silicon chain lengths were grafted onto a backbone of poly-diketo-pyrrolopyrrole-selenophene (PTDPPSe). The charge mobility can be enhanced with an appropriate increase of the silicon chain length. Most importantly, increasing the silicon chain length resulted in significant improvement of stretchability, including decreasing elastic modulus and increasing fracture strain. Interestingly, charge mobilities parallel to the stretching direction for PTDPPSe-4Si, PTDPPSe-5Si, and PTDPPSe-6Si are all above 1 cm2V–1s–1at 100% strain, higher than those of their unstretched states. This enhanced charge mobility is attributed to the excellent ductility and high strain-induced alignment of polymer chains. The current study is expected to provide guidance for the design of intrinsically stretchable polymer semiconductors and advance the development of wearable electronics.

ABSTRACTThe key role of circular RNA (circRNA) in the malignant progression of cancers has been demonstrated. However, the role of circRNA midline-1 (circMID1) in prostate cancer (PCa) progression has not been clarified. Quantitative real-time PCR was used to measure relative expression. Function analysis was performed using EdU staining, colony formation assay, flow cytometry, wound healing assay, transwell assay and cell glycolysis detection. The protein levels were detected by Western blot analysis. RNA pull-down assay, dual-luciferase reporter assay and RIP assay were performed to verify RNA interaction. Animal experiments were utilized to explore the effects of circMID1 knockdown on PCa tumorigenesis in vivo. Our results showed that circMID1 was upregulated in PCa tissues and cells and its knockdown inhibited PCa cell proliferation, migration, invasion and glycolysis in vitro, as well as PCa tumorigenesis in vivo. IGF1R and YTHDC2 were highly expressed in PCa tissues and cells, and their expression was positively regulated by circMID1. IGF1R and YTHDC2 overexpression reversed the inhibitory effect of circMID1 silencing on PCa cell progression. In terms of mechanism, circMID1 could sponge miR-330-3p and miR-330-3p could target IGF1R and YTHDC2. Functional experiments showed that circMID1 sponged miR-330-3p to regulate PCa progression via the YTHDC2/IGF1R/AKT axis. In conclusion, our data confirmed that circMID1 might play a pro-cancer role in PCa, which promoted PCa progression through regulating the miR-330-3p/YTHDC2/IGF1R/AKT axis.

The development of intrinsically stretchable n-type polymer semiconductors is highly desirable for various wearable and implantable electronics. However, very few studies have reported high-performance stretchable n-type conjugated polymers by molecular engineering. Herein, high electron mobility preservation under high stretch-strains is achieved by changing the type of grafted side chains as well as increasing the density of grafted side chains. A series of bis(2-oxoindolin-3-ylidene)-benzodifuran-dione (BIBDF)-based conjugated polymers with different side chains including alkyl chains and hybrid siloxane-based chains was synthesized to investigate the structure–property relationship. The experimental results demonstrated that replacing branched alkyl side chains with linear hybrid siloxane-based side chains and increasing the density of side chains greatly reduced the crystallinity of films and improved the flexibility of polymer chains. The resulting polymer CSi-PBIBDF showed significantly enhanced mechanical properties while maintaining high electron transport properties. Surprisingly, the electron mobility parallel to the stretching direction for the CSi-PBIBDF thin film reached 0.21 cm2V–1s–1at 100% strain, which is higher than that of the unstretched state, attributed to the stretch-induced alignment of the polymer chain. The current study demonstrated that systematic side chain engineering is extremely important to achieve high-performance stretchable n-type polymer semiconductors.

A series of conjugated polymers on the basis of diketopyrrolopyrrole and thienothiophene with different lengths of linear hybrid siloxane-terminal side chains were designed and synthesized. The number of silicon atoms in the side chains was 3, 5, and 7 (PTDPPTT-Si-3, PTDPPTT-Si-5, and PTDPPTT-Si-7, respectively, with two accompanying reference polymers, PTDPPTT-Ref-1 and PTDPPTT-Ref-2). Compared with PTDPPTT-Si-3, PTDPPTT-Si-5 and PTDPPTT-Si-7 had longer siloxane-terminal groups, which allowed them to maintain higher solution processability and excellent mobilities of 2.44 and 2.18 cm–2V–1s–1, respectively. In addition, the extended siloxane segment has high flexibility, which provides a good opportunity to improve the mechanical properties of rigid conjugated polymers. PTDPPTT-Si-7 exhibited excellent ductility and a low tensile modulus of 108 ± 21 MPa and retained 80% of its initial electrical properties under 100% stretching, indicating that long linear siloxane side chain-modified semiconductor polymers have great potential for wearable electronics. Our research provides an important guiding principle concerning the molecular engineering of semiconductor polymers with siloxane side chains.

Developing nonchlorinated solvent-processed polymeric semiconductors to avoid environmental concerns and health hazards caused by chlorinated solvents is especially urgent. Here, a molecular design strategy, composed of backbone fluorination and side chain optimization, is used for preparing high-solubility and high-performance azaisoindigo-based polymers. The effects of different backbones and side chains on the solubility, film crystallinity, molecular stacking, and charge transport properties are mainly investigated. A long linear hybrid siloxane-based chain (C6-Si7) is chosen to improve the solubility, while the incorporation of fluorine (F) is used to enhance the film crystallinity and charge mobility. By optimizing the backbone and side chain, both solubility and charge mobility of the azaisoindigo-based polymer are significantly improved. As a result, PAIIDBFT-Sifilms processed with toluene, tetrahydrofuran, ether, and alkanes, achieved charge mobilities of 4.14, 3.78, 2.14, and 2.34 cm2V–1s–1, respectively. The current study provides an effective strategy for the design and synthesis of high-performance polymeric semiconductors processed with nonchlorinated solvents.

Triboelectric nanogenerators (TENGs) have been widely applied for energy harvesting and self-powered sensing, whereas smart deformable materials can be combined with the TENG to acquire a more intelligent and self-adaptive system. Here, based on the vapor-driven actuation material of a perfluorosulfonic acid ionomer (PFSA), we propose a type of humidity-responsive TENG. The integrated TENG array can automatically bend to the desired angles in response to different humidity conditions, and thus, it can effectively collect energy from both wind and rain drops, where the power density can reach 1.6 W m–2at a wind speed of 25 m s–1and 230 mW m–2under rainy conditions. Meanwhile, this TENG array can fully lay down in dry weather, using the reflective surface to reflect sunlight and heat radiation. The vapor absorption process of the PSFA film can also result in the charge accumulation process. Accordingly, relying on the strong absorption capability of PFSA, a TENG-based vapor sensor with high sensitivity has been developed for monitoring chemical vapor leakage and humidity change. This work opens up a promising approach for the application of the humidity-responsive materials in the field of energy harvesting and self-powered sensors. It can also promote the development of TENG toward a more intelligent direction.

The collection of water from fog is a simple and sustainable means of obtaining freshwater for human and animal consumption. Herein, we address the use of metal foam in fog collection and present a novel fog-collecting device fabricated from copper foam. This device, which can also be used in other liquid–gas separation applications, is a 3D extension of biologically inspired 1D and 2D materials. The network structure of the 3D material effectively increased the contact area and interaction time of the skeleton structure and fog compared to those of traditional 2D fog-collecting materials. The main aspects investigated in this study were the influences of the inertial centrifugal force generated by rotating the metal-foam samples and the use of samples with different surface wettabilities on the fog-collecting performance. Superhydrophilic and superhydrophobic samples were found to have higher collection efficiencies at low and high rotational speeds, respectively, and a maximum efficiency of 86% was achieved for superhydrophobic copper foam (20 pores per inch) rotated at 1500 rpm.

Blending semiconductor polymers (SPs) with insulator polymers (IPs) is an effective strategy for preparing high-performance stretchable electronics. The key is the continuity of the semiconductor structure in the blend films, so the precise regulation of phase separation is the major challenge. Here, two key strategies that influence blend films were systematically investigated, including optimizing the solution-processable technique and controlling the semiconductor molecular weight (labeled LSP for 23.5 kDa, MSP for 108.5 kDa, and HSP for 222.6 kDa). Compared to the spin-coated (SC) films, the assembly on water-surface (AOW) films have uniform morphology, ordered microstructure, and better charge transport properties. During the formation of AOW films, SPs and IPs tend to move toward air and water, respectively, yielding a vertical phase separation structure. Moreover, a proportion of SPs are embedded in the SEBS matrix, with LSP forming an aggregated island structure and HSP forming a nanobunch network structure. For LSP, the introduction of an appropriate amount of SEBS can assist in the formation of an ordered film microstructure. The average mobility of the blend film LSP-SEBS (30%) is around 2.52 cm2V–1S–1, much higher than that of the neat film LSP (1.03 cm2V–1S–1). For HSP, the mechanical properties can be significantly improved by tuning the amount of SEBS, while maintaining favorable electrical properties. The highest mobility at 100% strain was calculated to be 0.73 and 0.21 cm2V–1S–1, for the blend film HSP-SEBS (70%) and the neat film HSP, respectively. Therefore, this study shows that optimizing the solution-processable technique as well as controlling the semiconductor molecular weight are promising and effective strategies for developing blend films, with good electrical and mechanical properties.

Anodic bonding technique has been extensively utilized in the micro-electromechanical systems (MEMS) packaging or solar cell sealing. Nevertheless, the traditional power source for bonding method needs both high voltage and high current, which limits the widespread applications of anodic bonding and also gives rise to energy consumption. Therefore, for the first time, triboelectric nanogenerator (TENG) is used to drive anodic bonding. The TENG-based Anodic bonding system features lower current and much less transferred charges requirement, while no pre-tensile strength of the bonded pairs is needed to achieve completed bonding. Under the drive of TENG, the silicon-glass interface with the size of 100 mm2can be tightly bonded within 40 s, which is comparable with the results driven by commercial power source. In addition, triple-stack anodic bonding driven by TENG through a two-step bonding process can be realized effectively with good reliability. This TENG-based Anodic bonding system with simple design and zero power consumption can significantly improve applications of anodic bonding in many fields, while it also opens up a promising utilization direction of the current signal of TENG.