Novel Hydrogel Allows Assembling Soft Robotic Components

Dynamic hydrogel material can be used to assemble microfluidic components with complex properties similar to LEGO blocks.

A team of researchers at the Brown University, Rhode Island, have developed dynamic hydrogel which can be used to make soft robotic components and can be used in biomedical applications. The hydrogel components are patterned with the help of a 3D printer which can be twisted or bended according to chemical treatments. The study was published in the journal Polymer Chemistry on March 21, 2019.

The research team demonstrated that the gripper being soft was capable enough to lift things. They also developed hydrogel blocks similar to LEGO set which can be packed tightly to obtain microfluidic devices for biomedical applications such as cell cultures and drug screening. The team claimed that the dual polymer property was responsible for the bending and twisting of the components. The hydrogel components solidify with crosslinking process holding the ionic and covalent bonds together. To prepare the novel material, the research team combined PEGDA, covalently cross-linked and PAA, ionically cross-linked. The former bonds hold the material whereas the latter bonds make the material responsive. When the material enters the ionic environment, it becomes more rigid and taking the ions away results in the material to become soft breaking the bonds.

Thus, this combinations of bonds allowed the researchers at the Brown University to make a soft gripper in which the fingers had PEGDA on one side and mixture of PAA and PEGDA on the other. The shrinking and strengthening of the side, allowed the two fingers to pull together. This allowed the soft gripper to hold onto objects with light weight. Furthermore, the hydrogel can be design microfluidic devices by adding ions to assemble them similar to LEGO blocks. Currently, the researchers are working on the extreme complex properties concerning durability to use it for future advancements.