Producing bright light from electromechanical forces in bendable, stretchable electronics

Flexible and wearable electronics are gradually accruing more attention as the technology to support them becomes more available. One of the biggest challenges centers around power supplies; wearable electronics need to be thin and deformable, but batteries are often rigid and bulky. As a result, many such devices rely on alternate means of producing energy.

Song et al. developed a device that emits light entirely by electroluminescence and mechanoluminescence. Their device produces a constant, intense brightness while remaining flexible and durable.

“Our work describes the fabrication of a light-emitting device that simultaneously produces the above two light emissions,” said author Soon Moon Jeong. “In particular, to obtain intense light, the stretchable silver nanowires were embedded in the emissive layer and arranged within an in-plane direction.”

In contrast to previous designs, where the emissive layer was controlled by an external electric field, the researchers embedded silver nanowires directly into the layer, producing an internal electric field. This has the benefit of allowing for a thicker emissive layer and consequently much brighter light. In addition, the design eliminates external electrodes, which can also block light transmission.

In addition to wearable applications, the team believes their device could be used in many other scenarios where flexible, durable electronics are needed.

“At the current stage of development, our proposed structure could potentially be used in large-scale outdoor billboards or light-emitting banners without high resolution requirements,” said Jeong. “Our proposed device is advantageous for outdoor applications due to its high resistance to environmental factors and its simple device structure without vacuum processes.”

Source: “Bright and uniform light emission from stretchable, dual-channel energy conversion systems: Simultaneous harnessing of electrical and mechanical excitations,” by Seongkyu Song, Hyeon-Seo Choi, Chang-Hee Cho, Sang Kyoo Lim, and Soon Moon Jeong, Applied Physics Reviews (2022). The article can be accessed at https://doi.org/10.1063/5.0080090 .