Microbots for Health, Engineering & Rescue

July 14, 2020

Robots can prepare human food, provide social interaction and build automobiles. These robots may be larger than a human or small enough to hold in your arms. But other robots in development range from the size of a penny to the width of a hair. Though not complete, these microbots promise to reach new technological advances and achieve new robotic applications.

Targeted Medication Delivery & Surgery

One robot, several times smaller than a penny, uses jet propulsion to travel in a hydrogen peroxide solution. The robot carries two polymer tubes containing a tiny amount of platinum that reacts with the solution and expels oxygen bubbles, producing thrust. An external transmitter steers the robot and triggers the heating of an induction coil that causes the chemical reaction. The robot could be used to deliver medicine within the human body but needs to be adapted to operate in a more biocompatible solution.

Swiss researchers have developed elastic folding robots inspired by bacteria. They are made of hydrogel nanocomposites with magnetic nanoparticles and are controlled by an electromagnetic field. These robots can travel through fluids and are small enough to pass through blood vessels. The robots fold to alter their shape when encountering a change of viscosity, which allows them to maintain speed and maneuverability. They could be used to deliver medicine to specific places in the body.

A spider robot might one day perform minimally invasive surgery. The robot moves through pneumatic and hydraulic power and has 18 degrees of flexibility – with the ability to move multiple joints in its legs and flex its abdomen. The robot’s body is made of elastic silicone. Such “soft robots” could navigate delicate human body structures and be used to repair tissue or destroy tumors.

Engine Repair & Macrostructure Building

HAMR-E is a cockroach-like robot that uses electric static to walk upside down and on curved surfaces. The previous model of the robot, HAMR, could swim through water but only walk on flat surfaces. Researchers designed the 1.8 inch robot to explore if it could aid mechanics by crawling into airplane or automobile engines without the need to dismantle them. The newest model, HAMR-JR, decreases the original robot to half its size – just larger than a penny.

Another bug-inspired engine-fixing robot in the works is known as SWARM and comes equipped with a tiny camera. Several of these microbots could be deployed into an engine and provide the mechanic with a video feed of the interior. Patch repairs would then be made with a companion robot that also delivers SWARM to the inspection site.

A team of microbots can build macro-scale structures, such as carbon fiber trusses. The robots are magnetic, smaller than a dime and travel on a circuit board that controls their speed and movement. They can join to form different shapes and build their own tools from droplets of curable liquid. These robots could work in manufacturing building tiny components or performing repairs inside larger robots and electronics.

Disaster Relief & Hazardous Inspection

RoboBee is a penny-sized flying robot. Researchers are still working out the combined constraints of size, weight, power source and flight. Currently, extra wings and solar panels have been added to aid untethered flight but RoboBee can only fly on its own for half a second. Ideally, the robot would function in a swarm with the ability to navigate and communicate autonomously. Originally conceptualized as robotic pollinators, the robot has applications in search and rescue, surveillance and environmental monitoring.

DARPA has launched the SHort-Range Independent Microrobotic Platforms (SHRIMP) program. The tiny robots would be able to reach areas inaccessible to larger robots for disaster relief and hazardous inspection. The program focuses on pushing technology to create optimal force generation, efficiency, strength-to-weight ratio and maximum work density.