Bio-Inspired Double-Layered Hydrogel Robot with Fast Response via Thermo-Responsive Effect.
Yunsong Liu1,2, Xiong Zheng1
1College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China.
Materials (Basel, Switzerland)
|August 10, 2024
Summary
This study presents a novel caterpillar-inspired hydrogel robot capable of ground locomotion. By enhancing thermal properties and hydrophilicity, the robot achieves faster movement and expands applications for soft robotics.
Area of Science:
- Soft Robotics
- Materials Science
- Biomimetics
Background:
- Thermo-responsive hydrogels are promising for bio-inspired robots due to safe human interaction.
- Current hydrogel robots are limited to underwater movement by hydration-dehydration processes.
Purpose of the Study:
- To develop a thermo-responsive hydrogel robot capable of terrestrial locomotion.
- To overcome the limitations of underwater-only movement in hydrogel robots.
Main Methods:
- Fabrication of an anisotropic double-layered hydrogel structure using interfacial diffusion polymerization.
- Incorporation of polyvinyl alcohol (PVA) and sodium alginate (SA) into poly(N-isopropylacrylamide) (PNIPAm) for enhanced hydrophilicity.
- Addition of iron(III) oxide (Fe3O4) nanoparticles to improve photo-thermal conversion and thermal conductivity.
Main Results:
- Reduced hydrogel contact angle from 53.1° to ~10° due to PVA and SA, decreasing hydration time.
- Decreased responsive bending time by 50% (from 1 hour to 30 minutes) through Fe3O4 nanoparticle enhancement.
- Achieved a terrestrial locomotion speed of 54.5 mm/h with excellent mechanical strength and flexibility.
Conclusions:
- The developed anisotropic hydrogel robot demonstrates efficient ground movement, overcoming previous limitations.
- Enhanced hydrophilicity and photo-thermal properties are key to improving hydrogel robot performance.
- This research opens new avenues for developing versatile soft robots for industrial applications.
