A so-called 'transformer battery' that transforms and moves on its own when exposed to light has been developed by domestic researchers.

The National Research Foundation of Korea announced that a joint research team consisting of Professor Lee Sang-young (Yonsei University, first author Kwon-hyung Lee, Ulsan National Institute of Science and Technology) and Professor Wi Jeong-jae (Inha University, first author Ji-su Jeon) has implemented a 'free-form power system' that integrates a liquid crystal polymer that changes shape due to light stimulation and a supercapacitor that can store energy.

▲Transformer batteries of various shapes (Photo courtesy of Professor Lee Sang-young of Yonsei University)

By freely controlling the molecular orientation and cell shape within the liquid crystal polymer, various shapes and deformations of the transformer cell were realized. The battery demonstrated stable operation even under deformation. The schematic diagram in the photo indicates the orientation direction of the liquid crystal molecules.

In fact, in the field of soft robotics, there are active attempts to create robots that can transform and move on their own and perform various roles such as information gathering and communication.

Existing soft robots have limitations in that they can only be supplied with electrical energy through external wires or fixed batteries, which has seriously hindered the movement and function of soft robots.

To implement a transformer battery, the research team integrated the battery material with a liquid crystal polymer using a microcomposite printing process.

In particular, shape deformation using light was effectively induced by utilizing the photothermal effect that converts light stimulation into heat. Additionally, the battery was designed using highly flexible materials such as conductive polymers and carbon nanotubes to ensure stable operation even during repeated movements.

The developed battery could be manufactured into various shapes, such as a coil, aperture, or palm, using printing techniques, and was freely deformed by light (or heat) stimulation.

Furthermore, we implemented a soft robotic power system that can carry objects and crawl to a set destination on its own.

▲Transformer battery that moves on its own to its destination (Photo courtesy of Professor Lee Sang-young of Yonsei University)

The photo shows a transformer cell moving on its own through light stimulation, safely transmitting electrical energy to its destination and turning on an LED. The figure on the lower left shows a schematic diagram of the battery configuration.

Professor Lee Sang-young said, “We expect that the developed transformer battery will become a fundamental technology that can practically implement soft robots,” and explained, “This is the first concept that a battery can change its shape and move on its own. We plan to conduct follow-up research to improve the battery’s energy and transform it into various shapes for future practical use.”

The results of this study, which was carried out with support from the Ministry of Science and ICT and the National Research Foundation of Korea's mid-career research and nano-material technology development projects, were published online on April 26 in the international materials journal 'Materials Today.'