Research Interest: functional architected materials, mechanical metamaterials, multiscale mechanics, additive manufacturing, soft robotics
Develop multi-stable structures and metamaterials with programmable morphing
Develop actuators and sensors for soft robotics
Thermal sensors and actuators: Morphable metamaterials that are integrated with time-dependent, highly deformable responses to environmental stimuli have allowed deployable mechanisms and soft robots to move or adapt their shape to their surroundings, as well as acquire novel features such as stretchability, growth, morphing, self-reconfigurability, self-healing, and edibility. Our research group will develop metamaterials that self-conforms around an object of interest as a physical route for computing and reporting the object’s shape.
Develop functional structures and metamaterials for aerospace applications
Develop meta-crystal lattices with phase transformation induced plasticity
Analogous to the rapid decreases in stress associated with dislocation slip in metallic single crystals, localized bands in metamaterials cause post-yielding collapse problems. However, in TRIP steels, the phase transformation between FCC and BCC structure induced outstanding plasticity. In our research, hardening mechanisms found in crystalline alloys are integrated into mechanical metamaterials to obtain the desired combination of outstanding strength and ductility.
Develop medical balloon catheters for Atrial Fibrillation (AFib) Treatment
Atrial fibrillation is the most common heart rhythm disturbance. It is caused by abnormal areas of the heart, causing disruption to the normal electrical beats in the heart. These areas can be treated by ‘ablation’ – a procedure in which parts of the heart are cauterised. To find these areas, we need to collect electrical signals directly from the surface of the heart. This needs many electrical wires to touch the surface of the heart wall at the same time (Fig. a). However, the signals are variable in the shape of electrical wires. The large nonlinear deformation of the current balloon catheter (Fig. b) is hard to be precisely predicted and controlled, making the signal collection difficult. The precisely controlled catheter tips can increase signal accuracy, save surgical time, improve the surgical success rate, and decrease medical costs. In this project, novel morphing metamaterials are proposed to provide precise motions, hence improving the accuracy of signal collection.
Develop metamaterial with structural hierarchy
As mechanical properties are highly coupled, there is a lack of design methodologies that can demonstrate one superior property without a trade-off in others. For example, most existing design methods achieve desired thermal actuation while penalizing elastic stiffness and vice versa. In this work, I present hierarchical bi-material lattices that are stiff and can be designed to attain a theoretically unbounded range of thermal expansion without (i) impact on elastic moduli and (ii) severe penalty in specific stiffness.
Routes to program metamaterials
Opportunities to tailor thermal expansion in architected materials exist, but design options that are stiff and provide full directional authority on thermal expansion are currently limited by the structural characteristics of existing concepts. In this work, we report routes to systematically engineer thermally responsive lattice materials that are built from dual-material tetrahedral units that are stiff and strong. Drawing from concepts of vector analysis, crystallography, and tessellation, a scheme is presented for three-dimensional lattices to program desired magnitude and spatial directionality, such as unidirectional, transverse isotropic, or isotropic, of thermal expansion.