Into the Fold: New Assistant Professor Creates Soft Robots Inspired by Origami and Biology

For Wenzhong Yan, joining the faculty of the Department of Mechanical and Aerospace Engineering at the University of California, Davis, is sort of a full-circle moment. Years ago, UC Davis was the first place he visited in the U.S., having grown up in China. 

“I flew with a friend who was attending UC Davis,” he said. “I loved the campus from the first moment.”  

Now, Yan returns to UC Davis as an assistant professor, eager to embark on new research collaborations that incorporate his focus on soft robotics, mechanical intelligence, origami and multifunctional materials, as well as to get to know his colleagues and take long, inspiring walks in the Arboretum.  

Finding Biomimicry  

Yan earned his Bachelor of Science degree in thermal engineering, as well as his Master of Science degree in aerospace propulsion theory and engineering, at Beihang University in Beijing.  

It was during his Ph.D. in mechanical engineering at UCLA that he learned about biomimicking, also known as bio-inspired robotics, which involves engineering machines that imitate biological structures or behaviors. He met an assistant professor there, Ankur Mehta, who was researching printable robotics inspired by origami shapes and rapid design and fabrication.  

Yan, who had been studying micro-electro-mechanical systems, or MEMS, felt his curiosity pique. The idea of using origami principles and compliant materials to develop soft robots that can bend and move like humans and animals seemed right up his alley.  

“It pulls together my interests in biology and animals and machines and creating machines like animals,” he said. “In the future, I will try to create a robot like a human or like animals that is very robust and can do useful things.”  

Yan was interested in this style of robotics, but his would-be advisor said there was no funding for this topic at that time. Yan was undeterred. He worked on his origami and robotics research at night while working as a paid programmer during the day, developing software to help people design furniture. Yan eventually completed his Ph.D. dissertation, titled “Printable Mechanical Autonomy,” shaped by his pastime research interests. 

In his dissertation, Yan presents a process for building fully autonomous folding robots without relying on computer chips or traditional electronics. Instead, these origami-inspired robots achieve autonomous behavior by embedding sensing, control and actuation directly into their materials and structure. 

Soft Robots, Big Leaps 

While at UCLA, Yan explored other research interests, like mechanical structures and materials. He and several collaborators developed a self-regenerative heat pump using electrocaloric polymer film stacks. The polymer film stacks change shape when an electric field is applied, creating a cooling effect and facilitating heat transfer without the need for other actuators, like motors or moving fluids. This lowered the temperature by 14 degrees Celsius, representing a major improvement over previous designs of similar cooling systems, which was published in Science. 

Yan describes the system as “simple” and “elegant,” and foresees its potential use in localized cooling applications, such as medical devices, wearable technology and computer chips.  

Yan and his UCLA colleagues also recently published a paper in Advanced Materials, describing a breakthrough in soft robot technology. The researchers developed an insect-scale robot that can jump continuously using only the power of light — no electronics at all.  

The robot is mainly made of liquid crystal elastomers, a soft rubber-like material that changes shape when exposed to light and can store and release energy when combined with a special curved beam. When light hits the robot, the material bends and snaps. The snap facilitates the jump, which also creates a shadow. The shadow blocks the light that hits the material, causing it to snap back automatically.  

Yan says he expected the robot to jump several times, but when it sustained 188 continuous jumps, that’s when he realized the experiment had exceeded expectations.  

“That was exciting and a surprise,” he said. “I did not plan for that.”  

Yan was also impressed by the material's robustness. The group experimented with adding weight to the robot, and there was no loss of performance, even when carrying up to 1,700 times its own body weight (which is approximately 300 milligrams, about the weight of a paper clip).  

Now Yan is collaborating with researchers at Yale, where he recently finished a postdoctoral research position, to make the robot deployable.   

One application that Yan is interested in exploring is wildfire monitoring and mitigation, which fits into his long-term vision of developing and deploying next-generation soft robots that integrate mechanical intelligence with computational intelligence to tackle critical societal challenges.  

“The rough idea is that they would [carry a sensor] and continuously jump. Once they detect smoke or a flame, they send a signal [to someone monitoring wildfires]. Basically, it would be a dynamic, distributed networking system that could detect lots of environmental factors.”  

Robots like these could also go into collapsed buildings, toxic or radioactive areas, or into narrow underground spaces. 

Walking, Wondering and Building What’s Next 

Yan says he likes to wander around whatever campus he is on to work out new ideas for research proposals or issues with current projects. At UC Davis, he is looking forward to taking most of his walks in the Arboretum.  

“When I saw the Arboretum, I said, ‘This is where I will spend one or two hours every day,’” he said.  

Upon joining UC Davis, Yan is eager to collaborate with his peers, including Assistant Professor Christina Harvey, an expert in bio-inspired technologies, and Professor Stephen Robinson, an expert in space exploration, both in the Department of Mechanical and Aerospace Engineering.  

Yan is considering a collaborative project to develop a wearable suit that adapts to the wearer’s needs.  

“Imagine if your T-shirt could be very rigid if you needed it to be, to support you and whatever harm you are facing. When you don’t need it [to be supportive], it can be very flexible,” he said.  

Outside of his department, Yan is interested in working with researchers in the Department of Biological and Agricultural Engineering. He imagines devising soft robots that can grasp and manipulate items, which would be ideal for picking delicate crops like strawberries or handling eggs with care.  

Yan is probably most excited, though, to get to know his fellow faculty members. Even before accepting the position, Yan was contacted by several, who had advice or questions about what he might need. Yan was touched by the exceedingly warm welcome.  

“You can collaborate everywhere, but it’s not everywhere you can find such good colleagues,” he said. “I’m very excited to join UC Davis as a faculty member.”