Scientists have created a new type of stretchable fabric-based battery powered by bacteria that eats your sweat–or any kind of bacteria-nourishing fluid–to produce electricity. It’s easy to imagine the long-term potential in the experimental prototype–one day, your clothes may charge your smartphone while you trot around the city.

For now, however, the researchers behind the battery are “targeting low-power Internet-of-Things applications,” as Binghamton University Electrical and Computer Science Assistant Professor Seokheun Choi told me over email. “Their throughput,” he said, “is not enough to power those smartphones yet.” The new battery is an evolution of a previous invention that used bacteria and paper, also developed by Choi’s team. Those paper batteries were capable of powering a LED light for 20 minutes on a couple of drops of dirty water, and were designed to be disposable.

This new biological power source, however, is designed to last. Instead of using paper as a substrate, it is embedded in an elastic fabric that can be stretched and twisted. In fact, according to Choi, the technology “exhibits stable electricity-generating capability when tested under repeated stretching and twisting cycles,” which makes it ideal to be embedded in any kind of clothing, including sports gear.

Choi is hopeful that their bio-batteries can make a difference in today’s power-hungry society, arguing that bacteria is everywhere in incredible quantities. “If we consider that humans possess more bacterial cells than human cells in their bodies,” he says in the release announcing the invention, “the direct use of bacterial cells as a power resource interdependently with the human body is conceivable for wearable electronics.”

The technology could have other applications, according to Choi. It can be used to embed self-powered sensors in any type of surface, no matter how complex it is, “like moving body parts or organs. We considered a flexible, stretchable, miniaturized bio-battery as a truly useful energy technology because of their sustainable, renewable and eco-friendly capabilities.”

It remains to be seen if these bacteria-based power sources could find a path to industrial manufacturing any time soon. Many other promising battery technologies have had a tough time coming to market due to immense economical and technical constraints. Still, I hope this one works out. The idea of charging my phone using my sweaty underpants as a source of infinite energy sounds absolutely perfect.