UNIST Researchers Develop Autonomous Bioinspired Power Source, Mimicking Electric Rays

UNIST researchers have successfully developed a novel energy harvesting technology that draws inspiration from electric rays. Unlike its biological muse, which requires mechanical stimulation, this innovative approach generates power autonomously without any external inputs. This groundbreaking development was spearheaded by Professor Hyunhyub Ko from the School of Energy and Chemical Engineering.

The BIAS Cell: High Voltage Generation

The research team fabricated a bioinspired bilayer ionic asymmetric stack (BIAS), an ionic heterojunction cell measuring a mere 0.2-millimeter thick. When multiple layers of these remarkable cells are stacked, they are capable of generating voltages exceeding 100V. This substantial voltage output allows for the direct operation of various electronic devices, including LED lights, calculators, and digital watches, eliminating the need for rectification.

Autonomous Power Generation: The Core Mechanism

The innovation's core lies in the cell's unique structure: an asymmetric bilayer composed of cationic and anionic polymer films. This specific configuration establishes an internal electric field that expertly facilitates ion migration, thereby producing a voltage akin to a biological membrane potential.

Unlike traditional ionic devices that rely on external stimuli, the BIAS spontaneously generates electricity through internal ion movement.

A single BIAS cell produces approximately 0.71V, a voltage more than 30 times higher than that achievable with symmetric structures. The ability to stack multiple cells ensures sustainable power for practical electronic devices.

Durability and Versatile Applications

The device demonstrates exceptional durability and environmental stability. It maintained its consistent voltage output even after more than 3,000 mechanical stretching cycles and tolerated elongation up to 1.5 times its original length without any degradation in performance. Furthermore, it operated reliably across a wide humidity range, from dry conditions to 90% humidity, exhibiting minimal power fluctuation. These robust characteristics strongly suggest its potential for widespread applications in wearable electronics.

Research Team Insights

First authors Seungjae Lee, Youngoh Lee, and Cheolhong Park highlighted that the BIAS unit cell, with its capability to generate high voltage autonomously when stacked, was developed by meticulously mimicking the ion-selective membrane potential observed in biological cells. Professor Ko further noted that this technology leverages internal ion migration within the bilayer structure to produce high voltage without any external energy source, which could significantly reduce maintenance requirements for wearable power sources.

Publication and Support

The significant research findings were officially published in Advanced Energy Materials on December 8, 2025. The project received invaluable support from both the National Research Foundation of Korea and the Ministry of Science and ICT.