Peeing on your socks could one day save yourself.

Researchers at the University of the West of England in Bristol, UK, have developed new socks that will allow you to use your urine to generate electricity in an emergency, according to an Engadget report.

The socks work because they have soft silicon tubes sin the heal that are connected to tiny fuel cells in the ankle. By simply walking, urine that has been connected in a bladder gets pumped into the fuel cells, resulting in an electrical charge — not much, mind you, but enough to transmit simple messages in the test, and providing the basis for future studies and developments that could result in more power and more applications.

If you think this would be a great last-minute Christmas gift idea, well, unfortunately you’re out of luck, as the socks are nowhere near ready for market. One major issue still facing the technology is how to get the urine into the socks, but if that issue can be fixed it has a variety of applications in the military and medical fields.

The findings were published in the journal Bioinspiration & Biomimetrics.

Here’s how the university described the system in a news release: “Soft MFCs embedded within a pair of socks was supplied with fresh urine, circulated by the human operator walking. Normally, continuous-flow MFCs would rely on a mains powered pump to circulate the urine over the microbial fuel cells, but this experiment relied solely on human activity. The manual pump was based on a simple fish circulatory system and the action of walking caused the urine to pass over the MFCs and generate energy. Soft tubes, placed under the heels, ensured frequent fluid push-pull by walking. The wearable MFC system successfully ran a wireless transmission board, which was able to send a message every two minutes to the PC-controlled receiver module.”