Tailoring Commercial Cellulose Membranes into Janus Conductive Electronic Skin via Diffusion-Controlled Polymerization

The mysterious ability of a lotus leaf to self-clean (upper surface is superhydrophobic and lower surface is superhydrophilic) has inspired the design of conductive Janus cellulose composite membranes with signal-capturing properties and biocompatibility of cellulose. Herein, diffusion-controlled polymerization was used to construct Janus conductive electronic skin. Specifically, dialysis membranes containing an aniline (ANI) solution were put into an APS solution. Due to the diffusion of APS, ANI polymerized inside the dialysis membranes and the thickness of polyaniline (PANI) could be controlled by the concentration of ANI. Finally, composite membranes (CDM-PANI) with Janus performance were achieved. The resistance of the conductive side of CDM-PANI showed an inverse proportional relationship with the thickness of PANI. When the thickness of PANI was increased to 1.37 mu m, the resistance of CDM-PANI became stable (55.3 Omega.cm). More importantly, the PANI layer that was decorated by the diffusion-controlled polymerization method imparted excellent firmness to cellulose-based membranes. The signal-capturing properties of CDM-PANI in response to tiny motions, organic gases, temperature, and illuminance of the membrane were studied, and these results demonstrated that the relative resistance of Janus membranes exhibited a good linear correlation with the concentration of organic gases, temperature, and illuminance. Therefore, the membranes could be used to detect the concentration and intensity of organic gases, temperature, and illuminance. This easy-to-tune strategy provided a new design philosophy for the fabrication of Janus conductive membranes.