A self-folding, robotic microgripper could one day make biopsies less invasive. The star-shaped devices are made from a carefully assembled arrangement of a hydrogel (N-isopropylacrylamide-co-acrylic acid), a polymer (polypropylene fumarate), and magnetic nanoparticles.
The soft hydrogel component swells in response to changes in light, acidity, and temperature. The polymer stiffens the otherwise floppy hydrogel, so that the swelling action yields the force necessary to perform a meaningful, grasping action. A magnetic probe can be used to steer the gripper, due to the embedded nanoparticles. The researchers involved in the project say that such an action could be used to extract a small tissue sample, or to help micro-engineer soft or biological parts. The grippers don’t need power delivered via a bulky power cord in order to operate, and would therefore make biopsies less invasive.
A new paper detailing the design and fabrication of the little robots can be found in ACS Applied Materials & Interfaces.