Researchers use 3D printing to develop wearable device for generating energy from body heat

Scientists at the University of Washington have achieved a breakthrough in the development of wearable electronics. They presented a flexible and robust electronic prototype device that can convert body heat into electrical energy. This innovation could have a significant impact on the future of wearables and energy-efficient electronics.

The device presented in the specialist journal ‘Advanced Materials’ is characterised by its remarkable resilience. It still works perfectly even after being punctured several times and stretched 2,000 times. The lead author, Mohammad Malakooti, describes how it works: ‘As soon as you place the device on the skin, it uses body heat to directly power an LED.’

At the core of the device are rigid thermoelectric semiconductors, which are responsible for converting heat into electricity. These are surrounded by 3D-printed composite materials with low thermal conductivity, which optimises energy conversion and reduces weight. The necessary elasticity is provided by printed liquid metal tracks that connect the semiconductors. In addition, liquid metal droplets were embedded in the outer layers to improve heat transfer and maintain flexibility.

The research team sees a wide range of potential applications for their technology. In addition to wearables, the devices could also be used in data centres, where they could use the waste heat from servers and computers to generate energy. ‘Our devices can capture this heat and use it to power temperature and humidity sensors,’ explains Malakooti.

The team’s visions for the future even include integration into virtual reality systems to create hot and cold sensations on the skin or improve wearing comfort. For now, however, the researchers are focussing on developing efficient and durable wearables with temperature feedback.

The research was supported by funding from the National Science Foundation, Meta and The Boeing Company.