Soft machines are transforming the fields of robotics and biomedical devices. They are capable of sustaining large deformation and interacting safely with fragile objects and human beings. The recent advance of additive manufacturing allows the fabrication of soft materials into complex structures. Designing and fabricating soft structures with programmable actuation and desired functionalities are the major efforts in the field.
In this seminar, Prof. Lihua Jin of UCLA will talk about her group’s recent progress in controlling spatiotemporal reconfiguration of soft active materials (SAMs), which are important building blocks of soft machines. SAMs can change their shapes or volumes in response to external stimuli, such as light, heat and electric fields, through non-equilibrium kinetic processes. Using liquid crystal elastomers, hydrogels, and shape memory polymers as model SAMs, she will demonstrate how to predict their temporal responses by developing non-equilibrium field theories, and program their spatiotemporal reconfiguration by patterning the materials using advanced manufacturing tools.
Further utilizing the interplay between SAMs and external stimuli, and coupling of their kinetics and inertia allows them to achieve autonomous oscillation and self-sustainable actuation of SMAs. Tuning the properties of SAMs through sophisticated chemical synthesis is often challenging. To overcome this limitation, she will demonstrate how they are able to vary the responses of soft materials by designing and fabricating them into mechanical metamaterials, which are materials with microarchitectures. Their efforts in designing phase-transforming metamaterials and energy-absorbing metamaterials will be discussed.
Lihua Jin is an assistant professor in the Department of Mechanical and Aerospace Engineering at the University of California, Los Angeles (UCLA). Before joining UCLA in 2016, she was a postdoctoral scholar at Stanford University. In 2014, she obtained her Ph.D. in Engineering Sciences from Harvard University. Prior to that, she earned her Bachelor’s and Master’s degrees from Fudan University in 2006 and 2009.
Jin’s group conducts research on the mechanics of soft materials, stimuli-responsive materials, instability and fracture, soft robotics, and biomechanics. Lihua was the winner of the Haythornthwaite Research Initiative Grant from the American Society of Mechanical Engineers in 2016, Extreme Mechanics Letters Young Investigator Award in 2018, Hellman Fellowship in 2019, UCLA Faculty Career Development Award in 2020, and NSF CAREER Award in 2021.
Contact Michelle Murray for Zoom link.