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An Additive Manufacturing Technique for the Facile and Rapid Fabrication of Hydrogel-based Micromachines with Magnetically Responsive Components
Published on: July 18, 2018
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Hydrogel-matrix encapsulated Nitinol actuation with self-cooling mechanism
Manivannan Sivaperuman Kalairaj1, Hritwick Banerjee1, Chwee Ming Lim2,3
1Department of Biomedical Engineering, National University of Singapore Singapore ren@nus.edu.sg.
RSC Advances
|May 9, 2022
Summary
A novel Hydrogel-matrix Encapsulated Nitinol Actuator (HENA) uses hydrogels to trap heat from Nitinol, enabling self-cooling. This innovation enhances Nitinol actuator performance for robotics and biomedical applications.
Area of Science:
- Materials Science
- Robotics
- Biomedical Engineering
Background:
- Shape-memory Nitinol is a promising smart actuator material but suffers from high operating temperatures and slow cooling, limiting commercial viability.
- Hydrogels, with high water content, can act as effective heat-trapping media.
Purpose of the Study:
- To develop a self-cooling mechanism for Nitinol actuators.
- To improve the performance and applicability of Nitinol in mesoscale machines and robotics.
Main Methods:
- Fabrication of a Hydrogel-matrix Encapsulated Nitinol Actuator (HENA).
- Comparative thermal analysis against a Silicone Elastomer Nitinol Actuator (SENA).
- Testing of HENA for bending displacement and soft robotic gripping capabilities.
Main Results:
- HENA maintained a surface temperature of 20-22 °C, significantly lower than SENA's 65-90 °C.
- HENA entrapped 85% of heat over 200 cycles, while SENA dissipated heat rapidly.
- HENA demonstrated a 45% bending displacement for potential trans-oral navigation and a soft gripper capable of lifting 450% of its weight.
Conclusions:
- HENA offers a novel self-cooling solution for Nitinol actuators, overcoming previous limitations.
- The HENA system shows great potential for advanced robotic applications, including delicate object manipulation and biomedical navigation.
