Stimuli-responsive cylindrical hydrogels mimic intestinal peristalsis to propel a solid object.

Area of Science:

• Soft robotics
• Biomimetic materials
• Hydrogel actuators

Background:

• Soft robotics requires materials that can move and adapt in complex environments.
• Replicating biological functions like muscle contraction and flexibility is key for advanced soft actuators.

Purpose of the Study:

• To demonstrate a soft actuator prototype capable of object transport and manipulation.
• To investigate the use of thermosensitive hydrogels for peristaltic motion.

Main Methods:

• Developed a hollow cylindrical actuator using poly(N-isopropylacrylamide) (PNIPAAM) hydrogels.
• Utilized Peltier devices for selective heating and cooling to induce a traveling wave of hydrogel deformation.
• Experimentally propelled a 4 mm diameter bead using the generated peristaltic wave.

Main Results:

• Achieved peristaltic transport of a 4 mm bead over a distance of 19.5 mm.
• Derived the conditions necessary for peristaltic transport based on transporter-cargo design parameters.
• Demonstrated the potential for hydrogel-based peristaltic manipulators to handle a wide range of cargo sizes.

Conclusions:

• Thermosensitive hydrogel actuators can effectively achieve peristaltic motion for object manipulation.
• Hydrogel-based peristaltic manipulators show promise for transporting cargo across a vast range of sizes (μm to m).
• The developed technology offers a versatile platform for soft robotics applications requiring precise movement and manipulation.