Researchers have developed a new shape-shifting micro robot that may someday be able able to swim through the blood stream to deliver drugs.
A team from the Thayer School of Engineering at Dartmouth College and City University of Hong Kong have mixed cardiac tissue engineering with a 3D printed wing coated with a light-sensitive gel to create a robot that can be started and stopped on command and transforms its shape when exposed to skin-penetrating near-infrared light.
“With this technology we can create soft transformable robots with unprecedented maneuverability,” Zi Chen, an assistant professor of engineering at Thayer, said in a statement. “Our inspiration came from transformable toys that have different configurations and functionality. The result is no toy, it may literally change people's lives.”
The remote-controllable robot includes a tail fin that simulates how whales swim through the ocean waters and a 3D printed structure in the shape of an airplane wing that is coated with heart muscle cells to propel the device through constant undulating action, similarly to how cardiomycytes cause the heart to continuously beat.
Photosentivie hydrogels that were applied to the robot’s wings allow the researchers to control its movements. When there is no skin-penetrating near-infrared light, the robot’s wings deploy while the heart cells propel the device forward.
However, when exposed to light, the floating plane retracts its wings, which causes it to stop in its tracks.
“The heart muscles keep churning, but they are unable to overcome the stopping power of the wings,” said Chen. “It's like pushing the accelerator pedal with the emergency brake on.”
To test the viability of the light-controlled robot, the researchers used it as a drug delivery system targeting cancer cells.
“We literally dropped drug bombs on cancer cells,” Chen said. “The realization of the transformable concept paves a pathway for potential development of next-generation intelligent biohybrid robotic systems.”
Because the device is highly sensitive to the light, a response rate is created that allows the wing to almost immediately transform its shape and the entire device to become highly maneuverable.
The study is part of an ongoing effort to create robots that mimic the shape-changing behavior of animals found in nature, such as how birds are able to spread their wings to fly and hedgehogs curl their bodies into a ball as a defense mechanism.
Researchers have had difficulties in the past creating a robot that fluently transforms its shape in respond to stimuli like heat or light, that allow it to start and stop moving on demand because most existing systems depend on temperature variations that are challenging to stimulate in the human body due to its nearly-constant temperature.
“The ability to control the robot's motion using light creates a much more functional device that can be operated with high precision,” Xiaomin Han, a recent PhD graduate from the Chen Research Lab at Thayer, said in a statement.
The researchers believe they can produce the robot in different sizes, ranging from several millimeters to dozens of centimeters, making it ideal to tackle difficult tasks in navigation and surveillance in different environments.
They also plan to test whether they can use light to target separate wings so that it can be steered with more precision.
The study was published in Small.