Tianjin University Team Achieves Major Breakthrough in Flexible Electronics and Embodied Sensing

A research team from Tianjin University has reported a major advance in flexible electronics and embodied sensing, developing a rapid and low-cost strategy that enables high-performance electronic circuits to tightly adhere to complex three-dimensional surfaces, advancing the practical application of electronic skin technologies in robotics.

The study, conducted by teams led by Huang Xian and Guo Rui from the State Key Laboratory of Precision Measurement Technology and Instruments at Tianjin University, in collaboration with Wang Hongzhang’s group at the Tsinghua University Shenzhen International Graduate School, introduces a heat-shrink fabrication strategy based on liquid-metal circuits and thermoplastic films. The findings were published in Nature Electronics.

Manufacturing high-performance electronic circuits on irregular three-dimensional surfaces has long posed a challenge in the field of flexible electronics. Conventional approaches such as 3D printing are often limited by high cost and low efficiency, while traditional lamination methods struggle to achieve reliable adhesion on highly curved or textured substrates. To address these issues, the researchers employed commercially available thermoplastic films that shrink upon heating and can tightly wrap around objects of arbitrary shape.

To prevent circuit fracture during the shrinkage process, the team developed a semi-liquid metallic material with high conductivity and good fluidity. Using a self-developed printing technique, electronic circuits were first patterned onto a flat thermoplastic film. With the aid of deformation simulations, the circuits were designed to follow a predefined transformation path during heating. When exposed to warm water or hot air at around 70 degrees Celsius, the film rapidly shrank and tightly adhered to three-dimensional surfaces within about five seconds. Experimental results showed that the resulting circuits exhibited excellent mechanical durability, maintaining stable electrical performance even after 5,000 cycles of repeated bending or twisting.

The technology has already demonstrated clear application potential. In the field of embodied intelligence, the research team developed customized tactile sensor arrays for robotic arms and heads, effectively endowing robots with sensitive electronic skin. They also created an intelligent glove integrating pressure and temperature sensors, enabling robots to identify objects through touch with an accuracy of up to 97 percent. Beyond robotics, the approach shows promise in smart agriculture, aerospace and healthcare, including temperature and humidity monitoring, aircraft wing de-icing and wearable health sensors. It also demonstrates reliable adhesion on challenging surfaces such as polytetrafluoroethylene, damp wood and rough plaster.

“These results open up a wide range of new application possibilities,” said Jiang Chengjie, first author of the study and a PhD researcher at the State Key Laboratory of Precision Measurement Technology and Instruments and the Department of Perception Science and Engineering at Tianjin University.

(By Qin Mian)