Outputting Olfactory Bionic Electric Impulse by PANI/PTFE/PANI Sandwich Nanostructures and their Application as Flexible, Smelling Electronic Skin

A new flexible smelling electronic skin (e-skin) has been realized from PANI(polyaniline)/PTFE(polytetrafluoroethylene)/PANI sandwich nanostructures basing on the triboelectrification/gas-sensing coupling effect. The e-skin can be driven by human motion/breath and efficiently convert mechanical vibration into electric impulse. And the output current/voltage is significantly dependent on the environmental atmosphere (volatile organic compounds in air), which can act as olfactory bionic electric impulse. Taking ethanol gas as an example, the detection limit of the e-skin at room temperature is 30 ppm, and the response is up to 66.8 upon exposure to 210 ppm ethanol. Interestingly, the response of the e-skin keeps stable with different dimensional sizes or under different strains/bending status. The working mechanism can be ascribed to the coupling of triboelectrification effect and surface reaction at the interfaces. Furthermore, an application of the flexible smelling e-skin for visually identifying drunken driver without any external electricity power has been demonstrated. The results can open a possible new direction for the development of specialized-function e-skin and will further expand the scope for self-powered nanosystems.