Generates Power Even When Folded Like Paper or Stretched Fivefold... KIST Develops Shape-Shifting Solar Cells [Reading Science]

3D Solar Structure Based on Origami Principles Maintains Performance After 1,000 Deformations
Provides Up to 225% of the Planar Installation Area for Solar Cells... With Potential Uses on Building Facades and in Space

A solar technology that can generate electricity even when folded like paper or stretched significantly has been developed. It can be installed on curved building facades and in narrow spaces, drawing attention as a technology that could overcome the limitations of conventional flat-panel solar cells.

The Korea Institute of Science and Technology (KIST) announced on October 14 that a research team led by Lee Philip, head of the Next-Generation Solar Cell Research Center, had developed a three-dimensional solar metamaterial structure that can be freely reshaped while maintaining its power-generation performance.

Root-like silver nanowires can improve surface properties and electrical conductivity, while the application method of liquid metal can give electrodes various functions. Courtesy of the research team.

Most existing solar cells are flat, making them difficult to install on curved surfaces or moving structures. Flexible solar cells also face problems when stretched significantly: the area available for placing the cells can shrink, or electrical connections can break.

The research team drew on the principles of "Kirigami" and "Origami," in which paper is cut and folded to change its shape. The structure was designed to transform into a desired shape when pulled or folded while keeping the network that conducts electricity intact.

The key is a new electrode technology. The team fixed fine silver nanowires to the surface of the structure and combined them with flexible liquid metal made of indium and gallium. The silver nanowires create pathways for electricity, while the liquid metal fills gaps in the network. The team also developed a way to attach and detach solar-cell modules without complex wiring.

An energy-generating system was developed using a structure that can be transformed into four configurations and conductive nanocomposites, allowing its stretchability and solar cell integration density to be increased according to its intended use. Provided by the research team.

Experiments showed that power-generation performance remained almost unchanged even when the structure was stretched to 500% of its initial length. It also maintained its performance after 1,000 repeated deformations. In a separate structure with densely arranged solar cells, the team achieved a solar-cell area of up to 225% of the planar installation area. Even when stretched by about 100%, the structure maintained a solar-cell area equivalent to its installation area.

No performance degradation was observed after the electrodes had been stored indoors for about two years, and they operated reliably in a 10,000-cycle repeated folding test.

From Building Facades to Space... Durability Remains a Challenge for Commercialization

Earlier this year, the research team developed a shape-changing solar system measuring about 900 square centimeters. In this latest work, the team succeeded in designing the structure's movement and electrical connections together.

However, further work is needed to ensure durability against strong winds and rain, develop mounting technology, and address fire safety before the system can be used on actual buildings. The team plans to develop technology to commercialize solar systems for building facades and expand their use to mobile platforms, portable power-generation devices, and deployable solar systems for space.

Photo of the KIST research team. Courtesy of KIST.

Hwang Seokjun, a postdoctoral researcher at KIST and the study's first author, said, "We plan to combine our earlier modular-structure technology with actual solar-cell modules to advance commercialization for architectural applications, and eventually expand its use to mobile platforms and deployable systems."

Lee Philip, the center director and corresponding author, said, "The significance of this study lies in designing the structure's movement, shape, and electrical functions together."

The findings were published in the latest issue of the international journal Advanced Materials.

This content was produced with the assistance of AI translation services.