A kirigami design where the length-to-width ratio of the cuts was six was much more responsive to magnets, which in turn enhanced an effect known as magnetically induced stiffening. Because there were no magnets around, the kirigami disk was much more flexible than a disk without cuts. But when a magnetic field was applied, it became more than 1.8 times stiffer.
In total, the kirigami dome could lift an object weighing 43.1 grams (28 times its own weight) to a height of 2.5 millimeters and hold it there. To test what this technology could do, Yin's team built a series of 5×5 domes powered by movable permanent magnetic pillars underneath that could move left or right or rotate. The array could accurately move drops, chips, a leaf, and even a small wooden plank. It can also spin a petri dish.
Next generation haptics
The team believes that a possible application of this technology is to accurately transport and mix very small quantities of liquids in research laboratories. But there is another, perhaps more exciting option. Chi's shape-shifting surface is very fast; it responds to changes in the magnetic field in less than 2 milliseconds, which is a response time that rivals gaming monitors.
According to the team, this makes it possible to use haptic feedback controllers. High-speed, magnetically powered shape-shifting surfaces can mimic the sense of touch, texture and feel of the objects you interact with while wearing your VR glasses. “I'm new to haptics, but since you can change the stiffness of our surfaces by modulating the magnetic field, this should allow us to emulate different haptic perceptions,” says Yin.
Before that becomes a reality, there is one more limitation the team must overcome.
If you were to compare Yin's shape-shifting surface to a screen where each dome represents a single pixel, the resolution of this screen would be very low. “So the question is how small can you make those domes,” says Yin. He suggested that with advanced manufacturing techniques it is possible to miniaturize the domes to a diameter of about 10 microns. “The challenge is how we manage at such scales – that is something we are focusing on today. We are trying to pave the way, but there is still much more to do,” Chi added.
Science Progress, 2024. DOI: https://doi.org/10.1126/sciadv.adr8421
