Researchers from the American Chemical Society (ACS) have developed small, swimming robots that can magnetically heal themselves.
If they break into two or three pieces while carrying out a task, the underwater machines simply piece themselves back together using a method the researchers devised to mimic the healing properties of living tissue.
The research, published in ACS' Nano Letters, adds to a growing field of robotics inspired by the natural world — such as these synchronized robot fish — that could help to monitor and clean the environment in the future.
The ACS team's robots can "swim" through fluids and carry out useful functions, such as "cleaning up the environment, delivering drugs, and performing surgery," a press statement explains.
Swimming robots that 'heal' whilst in motion
Swimming robots are typically made using brittle polymers or soft hydrogels, which have a propensity for cracking and tearing. Led by ACS' Joseph Wang, the team of researchers set out to design swimming robots that could "heal" while in motion, without help from humans or external triggers.
The researchers developed swimmers that were 2 cm long (roughly the width of a human finger) and shaped like a fish. These contained a conductive bottom layer, a rigid, hydrophobic middle layer, and an upper strip of aligned, strongly magnetic microparticles.
In order to give the robot propulsion, the team added platinum to its tail, which reacts with a hydrogen peroxide fuel to form oxygen bubbles.
As part of their investigation, the researchers placed the robot in a petri dish filled with a weak hydrogen peroxide solution. When it started moving around the dish, they cut the machine with a blade, and the tail kept moving around the dish. Once it approached the rest of the body, it re-attached through a strong magnetic reaction. The robot was also shown to heal when cut into three pieces.
The versatile, fast self-healing method could be an important, though modest, step towards robots that can repair themselves whilst on the job. Let's just hope they don't lead to self-regenerating Terminator-style robots down the line.