Imagine touching a flat metal surface and watching a button suddenly rise when a beam of light shines on it.
Researchers at the Korea Advanced Institute of Science and Technology (KAIST) have created a new technology that makes this possible, opening the door to future devices with pop-up buttons, shape-changing displays, wearable electronics, and soft robots.
The study, led by Professor Il-Kwon Oh from KAIST’s Department of Mechanical Engineering, was published in the journal Advanced Science.
Many future electronic devices are expected to be thin, lightweight, and flexible while still being able to change shape when needed.
Such technology could be used to create touch-sensitive surfaces, wearable devices, adaptive displays, and robots that move more like living creatures.
To achieve this, the KAIST team developed a special metal sheet made from a nickel-titanium alloy, also known as NiTi.
This material belongs to a group called shape-memory alloys, which can “remember” a preset shape. After being bent or flattened, they return to their original form when heated to a certain temperature.
Traditionally, getting these metals to respond to light has been difficult because NiTi does not absorb near-infrared light very well.
Researchers have usually solved this by adding special light-absorbing coatings, such as graphene-based materials or thin titanium nitride films. However, these coatings can wear off over time, make manufacturing more complicated, and even slow the metal’s response by adding extra material.
The KAIST researchers found a way around this problem by using a single ultraviolet (UV) laser process. The laser cuts tiny patterns into the metal while also changing its surface at the microscopic level. This creates a porous layer of titanium oxide that naturally absorbs near-infrared light much more effectively, eliminating the need for any additional coating.
The team also borrowed ideas from kirigami, the Japanese art of cutting paper to create three-dimensional shapes. By carefully designing tiny cuts and folding patterns in the metal sheet, they programmed exactly how the flat surface would rise into different three-dimensional forms when illuminated.
The researchers discovered they could control not only the final shape but also how high each section rises and how much force it produces. Even more impressively, they programmed different areas of the same metal sheet to move at different times, despite being exposed to the same light source. This was achieved by adjusting how much each area absorbed light, allowing the material itself to control the sequence of movement without wires or electronic circuits.
To demonstrate the technology, the researchers combined the metal structures with an array of near-infrared LEDs. Individual sections could be activated independently, allowing the system to display the letters “K-A-I-S-T” one after another. They also created raised touch patterns that could provide directional cues, showing how the technology might one day guide users through tactile feedback.
The researchers believe this simple manufacturing approach could lead to a new generation of intelligent surfaces that change shape using only light.
Future applications may include interactive displays with physical buttons, wearable devices that respond to touch, adaptive surfaces, and soft robots that move without complex wiring or bulky mechanical parts.
