'Wearable' polymer could charge phones from body heat

A new material that generates electricity from body heat could lead to clothing that can keep a mobile phone charged.

The material developed by scientists in South Korea is an organic thermoelectric generator (TEG) that produces an electric charge from the temperature difference between the body and the environment and can be formulated as a flexible, cuttable film.

The researchers from Yonsei University led by Eunkyoung Kim, synthesised a polymer based on an electrically conductive material known as PEDOT (poly(3,4-ethylenedioxythiophene)), which has been investigated for use protecting the cathodes and anodes in fuel cells from fouling.

Kim’s team combined a method to polymerise the material directly from solution with a reduction/oxidation reaction.

This produced a material that has a power factor — a measure of how much electricity can be produced related to the temperature difference — of 1270µM/m/K2, four times higher than any previous organic TEG.

The material is flexible enough to be incorporated into clothing and the team now hope to use the material to produce a wearable item that can harvest electricity from human body heat.

The research was published in a paper in the journal Energy and Environmental Science.