  Developing low-weight, frugal and sustainable power sources for
resource-limited settings appears to be a challenging proposition for the
advancement of next-generation sensing devices and beyond. Here, we report the
use of centimeter-sized simple wet fabric pieces for electrical power
generation, by deploying the interplay of a spontaneously induced ionic motion
across fabric channels due to capillary action and simultaneous water
evaporation by drawing thermal energy from the ambient. Unlike other reported
devices with similar functionalities, our arrangement does not necessitate any
input mechanical energy or complex topographical structures to be embedded in
the substrate. A single device is capable of generating a sustainable open
circuit potential up to 700 mV. This suffices establishing an inherent
capability of functionalizing self-power electronic devices, and also to be
potentially harnessed for enhanced power generation with feasible up-scaling.
