University of Michigan - Shanghai Jiao Tong University Joint Institute


Laboratory of Smart Solids and Structures (S-Lab)


Prof. Jaehyung Ju


S-Lab develops intelligent solids and structures having programmable mechanical properties by transformation of micro-architecture (often called “mesostructures” at ~mm cell size). The lab focuses on the understanding of the correlation of transformable micro-architecture to the macro-mechanical properties.

We design mechanical metamaterials whose mesostructures can be programmed with external stimuli – i) thermo-mechanical and ii) pneumatic controls.  The deformation controlled mesostructures will generate multi-mechanical properties with different Poisson’s ratios and thermal expansion coefficients.  On the thermo-mechanical control, the metamaterials design is integrated with advanced manufacturing methods, e.g., 4D printing fabricating mesostructures with multi-materials, programming the material’s function with time.

On the pneumatic control, we tune soft micro-architecture by embedding devices with internal air channels into core-movable members, generating motion of mesostructures. In principle, this is a soft robotics technique. The pneumatic control has an advantage for building programmable materials regarding fast response, large deformation and building highly rigid structures.

S-Lab uses an integrated approach – i) analytical modeling, ii) numerical simulations, and iii) experimental validation. We use (nonlinear) solid mechanics, kinematic mechanisms, mechanics of cellular solids, fabrication of programmable devices using (soft) robotics techniques, finite element (FE) based simulations, and experimental measurements.

While working on the fundamental research, we pursue an applied research on “nonpneumatic tires” where the PI has pioneered the development.