INNOVATIONS
PREPARE YOURSELF FOR TOMORROW
Transformers… activate!
Shape-shifting tech inspired by kirigami allows robot to change shape and function
This new soft robot (pictured above) can morph from a four-wheeled car into a drone and back again, with the application of a little heat.
To create this bot, a team at Virginia Tech needed to develop an entirely new type of flexible material.
“When we started the project, we wanted a material that could do three things: change shape, hold that shape, and then return to the original configuration, and to do this over many cycles,” says Michael Bartlett, an assistant professor who led the team.
“One of the challenges was to create a material that was soft enough to dramatically change shape, yet rigid enough to create adaptable machines that can perform different functions.”
To achieve this, the team took inspiration from kirigami – the Japanese art of making shapes out of paper by cutting and folding. Kirigami differs from origami, which only uses folding. It is popular among engineers since it gives paper the ability to support many times its own weight with the help of some smart geometry.
The final design was a kirigami-inspired grid of repeating geometric patterns, made of metal alloy. The alloy used was chosen for its low melting point of 60°C. Tendril-like heaters were woven around this frame so that an operator could apply heat to melt the metal and turn the material back to its original shape. The metal grid was then embedded into a rubber skin. The device could change and fix into place in less than one-tenth of a second, and the alloy was strong enough to repeatedly retain its desired shape, despite being stretched every time it transformed.
“These kirigami-inspired cuts, combined with the unique properties of the materials, were really important to morph, fix into shape rapidly, then return to the original shape,” said Dohgyu Hwang, a graduate student who co-authored the paper.
Edward Barron, Michael Bartlett and Dohgyu Hwang with their material 
The flexible material can quickly morph into various shapes 
It is comprised of a metal alloy grid embedded in rubber, with tendril-like heaters woven within it
The material was used to create various complex shapes, including a car (pictured at the top of this page) that could rapidly transform into a drone.
Looking to the future, this technology has clear potential. As well as a car-to-drone transformer, the team produced a prototype submarine that could retrieve objects from an aquarium by morphing its belly around a target item.
SMART TRANSFORMERS
WOUND HEALER
Using shape memory polymers (SMPs), a scientist at Virginia Tech has developed a material that can be formed into a temporary shape when exposed to heat. This could be applied to an injury where it would expand out to fill the wound when it reached body temperature.
INSPIRED BY NATURE
In a study published by the American Chemical Society, researchers printed liquid metal circuits onto a piece of polymer that curls under pressure. It could be used in soft robots to mimic behaviours seen in nature. This is normally hard to do, due to the clunky machinery that is needed.
ENERGY COLLECTOR
Researchers from the University of Massachusetts Amherst have created a rubber-like solid, capable of absorbing and releasing large amounts of energy. This could be used to enable robots to have more power, or even on helmets and armour to dissipate energy.