In the
never-ending quest to create robots that are ever more capable,
roboticists have often been inspired by creatures that nature has
designed. Attempting to mimic humans is a popular research area, as is
copying four-legged creatures. Efrati notes that most such animals have
one thing in common—stiff parts of their anatomy working against other
stiff parts produce motion—bones in joints, for example. But as Efrati
also notes, there is another area of research focused on the development
of softer components that are manipulated without stiffer
components—like jellyfish, for example, or flowers. Unfortunately,
progress in this area has been rather slow—soft machines tend to respond
slowly due to actuation issues. And they also tend to have limited
degrees of motion and wear out quickly. In this new effort, the
researchers have come up with a novel approach to creating soft
machines—combining the bendability of hydrogels with the power of air
pressure. They call their creations baromorphs, and they have
demonstrated that they can be used to create soft-machines in wide
variety of shapes.
Each baromorph is essentially a sheet of hydrogel
with channels inside of it. In its initial relaxed state, it is
typically flat. When air is pumped in, it is routed through the channels
in such a way as to inflate the baromoph into a desired shape. The
channels are designed using a computer program, which also handles the
formation of the resultant product. To prove the viability of their
method, the researchers created baromorphs that were shaped like bowls, a
saddle and even a human face.
More information:
Emmanuel Siéfert et al. Bio-inspired pneumatic shape-morphing elastomers, Nature Materials (2018). DOI: 10.1038/s41563-018-0219-x