A research team at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) has created a groundbreaking wearable device capable of harvesting electrical energy from body movements. This innovative three-dimensional stretchable piezoelectric energy harvester can be worn directly on the skin or clothing, converting mechanical energy from joint movements into electricity to power electronic devices.

Energy harvesters typically fall into two categories: those utilizing the Triboelectric effect and those relying on the Piezoelectric effect. The Triboelectric effect occurs when certain materials become electrically charged through friction, while the Piezoelectric effect generates electrical charge when mechanical stress is applied. The DGIST device takes advantage of the Piezoelectric effect, harvesting energy from everyday physical activities such as walking or joint movements.

Although several previous studies have focused on piezoelectric energy harvesters, many of these devices use organic or composite materials, which often struggle to efficiently capture energy from body motions. This inefficiency has limited their practical applications in wearable technology.

To address these limitations, the team, led by Prof. Jang Kyung-In, turned to lead zirconate titanate (PZT), a material known for its high piezoelectric efficiency. However, PZT is typically hard and brittle, which presents challenges for embedding it into flexible, stretchable devices.

To overcome these obstacles, the researchers designed the PZT material into a deformation-insensitive three-dimensional structure that ensures both high energy efficiency and the necessary stretchability for wearable applications. Additionally, they introduced a novel curvature-specific coupling electrode design that divides the electrodes into sections to prevent the cancellation of electrical output.

The result is a highly efficient and stretchable piezoelectric energy harvester that could revolutionize wearable technology. This new device is 280 times more efficient than traditional energy harvesters and is on track for potential commercialization, offering a promising solution for powering devices using only the natural movements of the human body.

By Impact Lab