Nanotube supercapacitors for wearables

The University of Surrey has led the development of a new type of flexible supercapacitor that could be embedded into wearables, clothing and footwear.

Based on carbon nanostructures, the device is the work of Surrey’s Advanced Technology Institute (ATI) and Brazil’s Federal University of Pelotas (UFPel). It was created by transferring aligned carbon nanotube (CNT) arrays from a silicon wafer to a polydimethylsiloxane (PDMS) matrix. This was then coated in a material called polyaniline (PANI) which stores energy through a mechanism known as “pseudocapacitance,”. According to the researchers, it provides excellent energy storage properties alongside exceptional mechanical integrity.

“Supercapacitors are key to ensuring that 5G and 6G technologies reach their full potential,” said Professor Ravi Silva, director of the ATI and Head of the Nano-Electronics Centre at the University of Surrey.

“While supercapacitors can certainly boost the lifespan of wearable consumer technologies, they have the potential to be revolutionary when you think about their role in autonomous vehicles and AI-assisted smart sensors that could help us all conserve energy. This is why it’s important that we create a low cost and environmentally friendly way to produce this incredibly promising energy storage technology. The future is certainly bright for supercapacitors.”

Published by the journal Nanoscale, the team’s paper details how a supercapacitor can be efficiently manufactured into a high-performance and low-cost power storage device that can be easily integrated into footwear, clothing, and accessories. According to the team, the wafer-thin supercapacitor retains most of its capacitance - the amount of separate electric charge that can be stored - after numerous cycles at different bending conditions, demonstrating robustness, longevity, and efficiency.

The project is the latest in an ongoing international collaborations between Surrey’s ATI, led by Professor Silva, and Brazilian higher education institutions. The initial research work was carried out in the ATI and consisted of the growth and characterization of materials, followed by electrochemical measurements carried out at the UFPel by Raphael Balboni and others from the NOVONANO group led by Professor Neftali Carreño.