Research

Nano-scale DIC Pattern Development 

We develop ultra-high-resolution digital image correlation (DIC) platforms for small-scale full-field deformation measurements. Using both electron-beam lithography and block-copolymer self-assembly approaches, we engineer nano-scale DIC patterns capable of resolving sub-nanometer (Ångström-level) displacements. Our research aims to directly visualize localized deformation and interfacial mechanical heterogeneity in advanced material systems with unprecedented spatial resolution. 

Residual Stress Mapping via Slitting-based Full-field Mechanics

Utilizing our nano-DIC platforms, we are developing slitting-based local residual stress characterization techniques for heterogeneous structures and semiconductor packaging systems. By precisely measuring deformation fields induced by stress relaxation during incremental slitting and combining them with linear elastic analysis, we reconstruct localized residual stress distributions with high spatial resolution. This approach enables quantitative diagnostics of mechanically complex systems where local stress evolution critically influences structural reliability. 

AI-assisted Indentation-based Property Evaluation 

We develop artificial neural network (ANN)-based frameworks for predicting small-scale mechanical properties from instrumented indentation data while explicitly accounting for experimental uncertainty. By establishing reliable indentation-to-tensile property conversion methodologies, our research enables accurate characterization of heterogeneous materials and localized interfacial regions where conventional mechanical testing is limited. These approaches are being applied to semiconductor materials, welded structures, and other complex material systems requiring high-fidelity local mechanical characterization. 

Environmental Nanomechanics under Coupled Conditions

We investigate the evolution of mechanical behavior and reliability under coupled environmental conditions through in-situ nanomechanical testing and operando experimental approaches. In particular, we perform hydrogen charging during indentation experiments to directly observe hydrogen-assisted mechanical degradation in metallic pipeline materials. Our research also includes stress-corrosion cracking (SCC) studies of polymer systems under harsh oxidizing environments to understand environmentally induced failure mechanisms across diverse material classes. Beyond these studies, we aim to establish operando experimental platforms capable of monitoring property evolution and deformation behavior of advanced material and device systems under realistic in-service and non-ambient conditions. 

Biodegradable Nano-cardboard Platforms for Near-space Applications

We are developing biodegradable nano-cardboard-based aerial platforms for environmentally sustainable near-space applications. Our research focuses on AI-driven multi-objective structural optimization to simultaneously achieve ultralight weight, high stiffness, and enhanced photophoretic lift performance. These aerial systems are composed of multifunctional composite materials, including ceramics and metals, and are designed to operate in the mesosphere, where conventional atmospheric observation technologies are limited. Such platforms could provide access to previously unobserved climate information and potentially serve as controllable aerial systems for solar engineering strategies aimed at mitigating global warming. 

Meta-structured Crack-based Sensors 

We develop highly sensitive crack-based sensors utilizing meta-structured and perforated mechanical architectures to amplify strain sensitivity and deformation localization. By combining computational mechanics simulations with experimental characterization, we systematically validate the sensing performance and structural reliability of these devices. Our research aims to establish mechanics-guided functional sensing platforms for next-generation wearable and multifunctional device applications.