Technique Speeds Up Thermal Actuation for Soft Robotics
December 16, 2021 | North Carolina State UniversityEstimated reading time: 2 minutes

Researchers from North Carolina State University have come up with a new design for thermal actuators, which can be used to create rapid movement in soft robotic devices.
“Using thermal actuation is not new for soft robots, but the biggest challenge for soft thermal actuators was that they were relatively slow – and we’ve made them fast,” says Yong Zhu, corresponding author of the paper and the Andrew A. Adams Distinguished Professor of Mechanical and Aerospace Engineering at NC State.
Actuators are the parts of a device – such as a soft robot – that create motion by converting energy into work.
“What makes this new actuator design work is a structure with a bi-stable design,” says Shuang Wu, first author of the paper and a Ph.D. student at NC State. “Think of a snap hair clip. It’s stable until you apply a certain amount of energy (by bending it over), and then it snaps into a different shape – which is also stable.”
In the case of the new thermal actuator, the material is bi-stable, but which shape the material prefers is dictated by temperature.
Here’s how that works. The researchers layer two materials on top of each other, with silver nanowires in the middle. The two materials have different coefficients of thermal expansion, which means they expand at different rates as they heat up. In practical terms, that means the structure bends when you heat it.
This layered material is then shaped into a design that gives it a default curvature in one direction – let’s say that it curves downward. When voltage is applied to the silver nanowires, the material heats up, making it bend in the other direction. Once you reach a certain temperature – the critical temperature – the material snaps into its new default shape, curving up rapidly. When the voltage is removed, the temperature goes back down. Once it cools past another critical temperature, the material snaps back to its previous default shape, curving down rapidly. Note that the two critical temperatures are different; the first one is higher. By applying current to the nanowires in a regular pattern, you can make the material snap back and forth.
To demonstrate the technique, the researchers created two prototypes. One of the prototypes emulates the snapping behavior of a Venus flytrap, while the other is a “crawler” capable of moving more than one body length per second.
“Potential applications range from biomedical applications to prosthetic devices to high-end manufacturing,” Zhu says. “Any application in which you’d want to be able to move quickly, but also want to avoid rigid materials and conventional robotics.”
Next steps include developing sensor and control mechanisms that could more fully automate the actuation process, allowing it to operate more efficiently than purely manual controls.
“We’re also interested in exploring other possible materials, so that we could fine-tune the thermal and mechanical properties,” Zhu says. “This could allow us to tailor both actuator speed and force.”
Read the original article, here.
Testimonial
"Advertising in PCB007 Magazine has been a great way to showcase our bare board testers to the right audience. The I-Connect007 team makes the process smooth and professional. We’re proud to be featured in such a trusted publication."
Klaus Koziol - atgSuggested Items
Mobix Labs Secures Surge of High-Value Defense Orders, Igniting Growth in its Filter Interconnect Products
07/23/2025 | BUSINESS WIREMobix Labs, Inc., a leading innovator of advanced connectivity and electromagnetic interference (EMI) filtering technology, announced significant quarter-over-quarter revenue growth in its filter and interconnect products, powered by strong customer demand and major wins across mission-critical defense and aerospace programs.
NEOTech’s Westborough Facility Achieves AS9100 Surveillance Audit, Reinforcing Trust with Aerospace & Defense Customers
07/22/2025 | NEOTechNEOTech, a premier provider of electronic manufacturing services (EMS), integrated design engineering, and advanced supply chain solutions for the aerospace and defense, medical device, and high-tech industrial markets, proudly announces that its Westborough, Massachusetts facility has successfully completed the rigorous AS9100 Bi-Annual Surveillance Audit with zero findings, a testament to the company’s unwavering commitment to quality, security, and operational excellence.
TT Electronics Secures Multi-Million-Pound Defense Contract with Ultra PCS
07/18/2025 | TT ElectronicsTT Electronics, a leading provider of global manufacturing solutions and engineered technologies, announced that it has been awarded a significant new contract with long-standing customer Ultra PCS Ltd (Ultra Precision Control Systems).
NEOTech’s Agave 1 Facility Earns AS9100 Certification for Commercial Aerospace Manufacturing Excellence
07/17/2025 | NEOTechNEOTech, a premier provider of electronic manufacturing services (EMS), integrated design engineering, and advanced supply chain solutions for the aerospace and defense, medical device, and high-tech industrial markets, proudly announces that its Agave 1 manufacturing facility in Juarez, Mexico has officially received AS9100 certification.
Federal Electronics Invests in HydroJet Inline Cleaning Technology at Hermosillo Facility
07/15/2025 | Federal ElectronicsFederal Electronics, a leader in providing advanced electronic manufacturing services, has strengthened the advanced cleaning capabilities of its Hermosillo, Mexico facility with the recent installation of a HydroJet Inline Cleaner from Austin American Technology (AAT).