“…Currently, many life-relevant gas molecules have been detected by scientists trying to set up self-powered sensors, like ethanol, 145–147 NH 3 , 45,148,149 CO 2 , 150,215 NO 2 , 151 acetone, 152 formaldehyde, 154 etc. For instance, Fu et al 146 reported a 5 cm × 5 cm × 10 μm PENG-driven sensor array which is based on polyaniline/polyvinylidene fluoride (PANI/PVDF); it illustrated responses to acetone, ethanol, CO, NO x , and CH 4 with a concentration from 0 to 600 ppm and the maximum response of each sensing unit to 600 ppm of gas markers is 68.2%, 56.9%, 47.1%, 105.1%, and 53.5%, respectively.…”