New Method May Lead to Hydrogel Based Soft Robots

North Carolina State University researchers have developed a method that creates devices from hydrogel, a water based poylmer material. The resulting device can be patterned, folded and used to manipulate objects. The research paper, "Reversible Patterning and Actuation of Hydrogels By Electrically Assisted Ionoprinting," is published in the online journal Nature Communications.

Hydrogels are polymers that are highly absorbent that can shrink and expand depending on outside conditions like humidity, pH levels, and temperature. Consumer products use hydrogels in contact lenses for its flexibility, baby diapers for its absorbency, and also in adhesives. Hydrogels are most known for its use as a drug delivery system. Hydrogel based capsules are a popular fixture in pharmacies around the world.

Previously, hydrogels were developed to react a certain way given certain specific conditions. But with the recent discovery, devices can now be developed that can be actively controlled in real time rather than being just reactive. By being able to control the structure and movement of hydrogel, researchers can create devices for use not only for biomedical purposes but also in the field of robotics.

These new devices can be used in the production of soft robots. Soft robots are robots that combine organic chemistry, soft materials science and robotics. These are different from industrial robots in that instead of using gears and motors for movement, soft robots use other means such as chemical reactions or compressed air to move. Soft robots are also made of other materials like rubber and silicon.

Quadruped Cheetah-Cub Robot Developed Through Biomechanics

Researchers at the Ecole Polytechnique Fédérale de Lausanne using biomechanics, have developed a four legged robot that can run like a cat, with speeds up to seven times its body length per second.

Biomechanics is the study of biological systems in humans, plants, and animals and its application to structure and function in mechanics. This field of science usually focuses on the application of artificial limbs and the study of the mechanical properties of soft tissue and bones.

The Cheetah-Cub robot's primary design feature are in its legs. The legs have been developed by closely studying and reproducing the functions and structure of a cat's leg. This allows the robot to be agile and fast just like that of a cat. The robot is about the size of a house cat and is lightweight. It mimics the movement of a cat and is fast for its size and weight; about 1.4 meters a second. It also can compensate for obstacles such as small steps and rough terrain (see embedded video below).

Researchers are looking at developing the cheetah-cub robot for use in search and rescue missions and also for exploration purposes as well. Developing quadruped robots can circumvent limitations that wheel based robots have when it comes to certain surfaces such as rocky terrain.