Robotic creepy-crawlies climb walls

Two teams of researchers have demonstrated tiny robots that use electrostatic forces to climb vertical surfaces

Once fully developed, such robots, which weigh less than two grams, could be used in a range of deployments, such as safety-checking inside hard-to-reach parts of jet engines, or performing search-and-rescue surveillance in collapsed buildings.

A team head by Sébastien de Rivaz from Harvard University’s John A. Paulson School of Engineering and Applied Sciences in the US report the creation of the Harvard Ambulatory MicroRobot with Electroadhesion (HAMR-E).

This machine is 4.5 centimetres long and weighs 1.48 grams. By generating an electrostatic force using a 250-volt input, the HAMR-E moves by means of three alternating adhesive pads.

In proof-of-concept tests, de Rivaz and colleagues showed that the mini-bot could move up a sheer vertical surface at 1.2 millimetres per second. It managed 215 steps before running out of fizz.

In a second study, researchers led by Guoying Gu from Shanghai Jiao Tong University in China, reveal “a tethered soft robot capable of climbing walls made of wood, paper, and glass”. 

The machine moves through a combination of dielectric-elastomer artificial muscles and electro-adhesive feet.

Gu and colleagues demonstrate that the bot can climb, crawl and turn, and can even vary its body height in order to fit through narrow gaps. It has enough strength to carry a 10-gram weight, meaning, the authors say, that it could be fitted with a camera.

At present, both the Harvard and Shanghai machines are wired to power supply, but the researchers are investigating ways to untether them and thus increase autonomy.

Both studies are published in the journal Science Robotics.