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Flexible planar microsupercapacitors (MSCs), with the advantages of small size, easy integration and expansion on electronic devices, have emerged as one of the most critical power devices in wearable and portable electronics. However, most processes involve independent preparation of electrode materials, patterned microelectrodes, and subsequent modular integration, making the steps very complicated. Herein, we have developed a novel, simple and one-step laser direct writing process to design planar shape-controllable MnO2 nanoparticles evenly embedded in laser-induced graphene (MnO2/LIG) MSCs on different flexible substrates. The obtained MnO2/LIG MSCs show an outstanding areal specific capacity of 15.04 mF cm−2, a high energy density of 1.22 mWh cm−2 at a good power density of 1.278 mW cm−2, good mechanical flexibility and remarkable modular integration due to effective design of pseudocapacitive MnO2 nanoparticles evenly embedded in highly conductive LIG with 3D porous structure. This universal manufacturing route for controllable assembly of flexible planar MSCs with other pseudocapacitive nanoparticles embedded into LIG, thus broadening their flexible and wearable application as a promising storage device to meet the modular integration and biocompatibility.

NO2 sensing devices derived from three-dimensional (3D) nanotube graphene (NTG) and ZnO nanosphere nanocomposite are proposed for room temperature (RT) operation. The nickel nanowires were grown chemically, then graphene was grown onto the obtained nickel nanowires via chemical vapor deposition (CVD). The 3D NTG was then prepared through etching the nickel nanowires, while synthesis of the NTG/ZnO composite was achieved via the hydrothermal method. The sensing performance of these NTG and NTG/ZnO gas sensors to NO2 was systematically investigated. The NTG gas sensor responded with a 22.5% change upon being exposed to 50 ppm of NO2, while the response of the NTG/ZnO device reached 47.8% when exposed to the same NO2 concentration. Furthermore, these devices were also capable of detecting concentrations of NO2 as low as 100 ppb. In addition, NTG and NTG/ZnO gas sensors were found to have good selectivity and repeatability. According to the analysis of the sensing mechanism for the NTG/ZnO composite, the high response of the sensing device is attributed to the heterostructure between NTG and ZnO. When the device is exposed to air and NO2, the barrier changes significantly, thus causing a change of resistance.

Cell membrane mimetic antifouling polymer brush was grown on polysulfone (PSF) membrane by surface-induced reversible addition–fragmentation chain transfer (RAFT) polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC). The RAFT agent immobilized PSF substrate was prepared by successive chloromethylation, amination with ethylenediamine (EDA) and amidation of the amine group of grafted EDA with the carboxylic group of 4-cyanopentanoic acid dithiobenzoate (CPAD). The surface RAFT polymerization of MPC was initiated in aqueous solution by 4,4′-azobis-4-cyanopentanoic acid (ACPA). The formation of PMPC brush coating is evidenced by X-ray photoelectron spectroscopy and water contact angle measurements. The degree of polymerization of PMPC and the polymer grafting density were calculated from the high resolution XPS spectra. The platelet adhesion and protein adsorption results showed that the PMPC-grafted PSF surface has excellent antifouling ability to resist platelet adhesion completely and suppress protein adsorption significantly. This biomimetic and bio-friendly surface RAFT polymerization strategy could be promising for a variety of biomedical applications.