May 9, 2013
Graphene forms transparent actuator
A transparent actuator developed by researchers in Korea could be used to make movable elements for touch-screens, or even vari-focal lenses. The actuator consists of a dielectric elastomer layer sandwiched between transparent and stretchable graphene electrodes, and a frame that links the materials to the substrate. When a voltage is applied, the dielectric elastomer film in the region of the top and bottom graphene electrode “bumps up” (see video).
The team, which includes scientists from Sungkyunkwan University (SKKU) and Seoul National University (SNU), reported that the actuator is 100 µm thick and produces a displacement of around 1050 µm. The sheet resistance of the graphene electrode used in the test setup was 92 Ω/square and the optical transmittance of the actuator was measured to be 84.5%.
In experiments the researchers demonstrated the application of a graphene electrode and OCA film as a novel actuator for use in tactile displays, and validated that the actuator can operate even when stretched to 25% of its length without severely degrading its actuating performance.
A touch interface can be formed by combining the actuator with a sensor to create functional touch-screen panel devices.
Full details can be found in the journal Nanotechnology.
About the author
The study was conducted by researchers from Sungkyunkwan University, Korea led by Prof. Hyouk Ryeol Choi with the collaboration of Prof. Hyungpil Moon, Ja Choon Koo and Jae-Boong Choi from the School of Mechanical Engineering, Jae-Do Nam from Polymer System Engineering; and Byung Hee Hong, who is based at Seoul National University, Korea. Uikyum Kim is a PhD candidate in the Intelligent Robotics and Mechatronics System Laboratory (IRMS) in the School of Mechanical Engineering at Sungkyunkwan University, Suwon, Korea, under the supervision of Hyouk Ryeol Choi, PhD. Kim is currently exploring dielectric elastomer as electromechnical transducers and nanoparticles for sensing and actuation. Junmo Kang is a postdoctoral researcher at Sungkyunkwan Advanced Institute of Nanotechnology(SAINT) and works on graphene-based polymer systems. Choonghan Lee and Hyeok Yong Kwon, who are masters students in the School of Mechanical Engineering at Sungkyunkwan University, fabricated the graphene electrode and performed the evaluation tests. Soonhwi Hwang is a masters student at SAINT and contributed to the synthesis of graphene.