Researchers at Columbia University have developed a robot which uses a newer bacteria based actuation which is controlled by humidity, envisioning a future of new and automated applications. The team, led by Ozgur Sahin, an associate professor of biological sciences and physics, managed to develop a material which is made of a combination of adhesives and spores,made of units which are produced by bacteria, which are able to be used as an alternative to synthetic polymers used in robotic actuators.
The actuators which are made with this particular material allows the tech to respond much quicker compared to current iterations constructed with traditional polymers. Actuators made with the new material can also generate a higher level of force and is water-resistant, able to use humidity to aid in determining their course of movement whilst actuators made of traditional materials fail once they come into contact with water.
In order to develop the material, the researchers at the university used a photochemical process to bind the tiny spores, which are individually water resistant. This process involves a high intensity ultraviolet light, similar to those used in nail salons to dry nail polish, to glue these spores together into a composite material. One member of the research team, Onur Cakmak, compared the entire process to making sheets of the surface from sand due to the granular nature of the materials present. Once hardened, the material is stacked in layers in order to form a microscopic structure which is able to expand or contract with humidity or moisture. This results in the the structure having the capability for force and mechanical movements.
The material can also be patterned, allowing researchers to create patterned designs which is able to guide the composite to bend, fold and unfold in response to humidity or water. Hence, these soft actuators are able to adapt to their surroundings and move with more agility as compared to their more traditional counterparts, allowing easier creation of useful systems from the materials.
However, due to how the new material is very different from the harder polymers which are usually in robots, which use metallic structures that require a computer to control the actuation, soft robots do not require a rigid skeleton or electricity in order to provide the system with mechanical strength. As a result, they are more easier and less expensive to fabricate, and are also more capable of comparably more complex motions, and are safer to use around humans.
The Columbia University research team sees numerous potential application for this new technology, ranging from applications within smart-energy buildings which include windows which automatically open when humidity levels grow too high, to developing high performance fabric for athletic clothing which helps sweat evaporate faster.