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Herein, we propose a highly sensitive wireless rehabilitation training ball with a piezoresistive sensor array for patients with Parkinson’s disease (PD). The piezoresistive material is a low percolation threshold conductive hydrogel which is formed with polypyrrole (PPy) nanofibers (NFs) as a conductive filler derived from a polydopamine (PDA) template. The proton acid doping effect and molecular template of PDA are essential for endowing PPy NFs with a high aspect ratio, leading to a low percolation threshold (∼0.78 vol %) and a low Young’s 004Dodulus of 37.69 kPa and hence easy deformation. The piezoresistive sensor exhibited a static and dynamic stability of 10,000 s and 15,000 cycle times, respectively. This stability could be attributed to the increased hydrophilicity of conductive fillers, enhancing the interfacial strength between the conductive filler and the matrix. The interaction between the PDA-PPy NFs and the hydrogel matrix endows the hydrogel with toughness and ensures the stability of the device. Additionally, the microdome structure of the conductive hydrogel, produced by hot screen-imprinting, dramatically improves the sensitivity of the piezoresistive sensor (∼856.14 kPa–1). The microdome conductive hydrogel can distinguish a subtle pressure of 15.40 Pa compared to the control hydrogel without a microstructure. The highly sensitive piezoresistive sensor has the potential to monitor the hand-grip force, which is not well controlled by patients with PD. The rehabilitation training ball assembled with a sensor array on the surface and a wireless chip for communication inside is built and used to monitor the pressure in real time through the WeChat applet. Thus, this work has significantly broadened the application of hydrogel-based flexible piezoresistive sensors for human activity monitoring, which provides a promising strategy to realize next-generation electronics.

A superhydrophobic fabric coating with hierarchical structure was fabricated by a dip coating, in which dodecyltrimethoxysilane (DTMS)‐modified alumina (Al2O3) was used as modifier and polydimethylsiloxane (PDMS) as additive. The effects of the amounts of Al2O3 nano‐sized particles and PDMS on the water contact angle (WCA) and the sliding angle (SA) of the as‐prepared fabrics coating samples were studied. The surface morphology of the as‐prepared samples was characterized by SEM, and the abrasion resistance and chemical resistance experiments were performed by abrasion resistance test, tape tear test, and chemical soaking test. The results show that WCA and SA of the superhydrophobic fabrics coating are 158° and 6°, respectively. With the increasing addition of PDMS, the abrasion resistance of hydrophobic fabrics coating is improved. The WCA value of the as‐prepared fabrics coating is still >150° after five abrasion cycles. The obtained fabrics exhibit excellent superhydrophobicity and oleophilicity due to the hydrophobic modification of DTMS for Al2O3 nano‐sized particles. And the separation efficiency of the as‐prepared superhydrophobic fabrics coating for n‐dodecane and water system can reach 99.98%. POLYM. COMPOS., 2018. © 2018 Society of Plastics Engineers

A superhydrophobic surface with micro-nano rough structure and corrosion-resisting property was prepared on aluminium substrate by a simple one-step wet chemical etching in HCl solution and in situ polymerisation method through thiol-ene coupling. The influence of etching time on wettability and morphology of the aluminium substrate surface was discussed. The surface morphology, chemical compositions and wettability of the aluminium substrate were investigated by scanning electron microscope, energy-dispersive X-ray spectroscopy and Fourier transform infrared. The water contact angle (WCA) and sliding angle (SA) were measured to study the superhydrophobicity. The results showed that a rough and irregular morphology was formed with 3.5 min etching, WCA and SA of the modified aluminium surface were 163°and 5°, respectively. The as-prepared surface revealed excellent corrosion resistance in 3.5% wt NaCl solution. The self-etching current density of the superhydrophobic aluminium surface was only 3.22 × 10 −7 A cm −2 .