Called liquid crystal elastomers (LCEs), shape memory polymers are increasingly popular for use in haptics, soft robotics, and wearable computing. LCEs can function as actuators and they can allow materials to contract, expand, shape, change, and perform how biological muscles do.
Since the action is controlled via heating and passive cooling, initiatives to accelerate processes and increase energy efficiency are crucial for advancement of the work.
A multidisciplinary team of researchers at the Department of Mechanical Engineering, Robotics Institute, and Human-Computer Interaction Institute of Carnegie Mellon University sought to tackle the challenge by consolidating LCEs with a thermoelectric device.
The collaboration led to development of a soft, flexible procedure capable of electrically controlled actuation, thermal-to-electrical energy conversion, and active cooling. The collaborators also introduced a new manufacturing process for stretchable and bendable thermos electric devices using 3D printing.
The findings are published in Advanced Materials.
The LCE-TED mechanism works as a transducer – an electrical device that converts one form of energy into another. A thin layer of TED contains semiconductors implanted within a 3D printed elastomer matrix. The TED is wired liquid metal connections of eutectic gallium-indium.
In terms of function, TEDs work with dual functionality as coolers as well as heaters in one mode and energy harvesters in the other. Since the layer is covered with LCEs on both sides, the TED can alternately cool and heat LCE layers. Additionally, it can harvest energy from changes in temperature.
Meanwhile, the ability to recover energy from thermal gradients and residual heat could assist with improved energy efficiency and longevity of host robotic system or electronic device.
In fact, soft robotics demonstrations reveal advantages of LCE-TED transducers for use in practical applications.