Research

Current research in the Xia group is focused on nanomechanics of structured and functional composite materials. For structured material systems, we study the interface and mechanical properties of nanocomposites, woven and hybrid composites, and biomimetic materials. For functional material systems, we study the coupling phenomena (electrical, thermal, mechanical, etc.) in composite materials for sensing and damage detection. The critical issues under investigation include stiffness, toughness, buckling, nanocontact, adhesion, friction, diffusion, size effects, electro-mechanical and thermo-mechanical coupling, etc. Our work is also expanded to catalysts for clean energy conversion technology including fuel cells and batteries.

 

ecko-mimic self-clean and micromanipulator 
Self-cleaning and micromanipulation mimicking
gecko spatulae, published in Nature Communications 
6, 8949 (2015). Read the story

Gecko-mimic self-clean and micromanipulator

Design principles for  carbon-based catalysts
Design principles have been established for doped
carbon (Adv. Mater. 2015) and  covalent organic
frameworks (Adv. Mater. 2017).
Nature Energy 1, 16155 (2016). Read commentary

Design principles for  carbon-based catalysts

Metal-free bifunctional electrocatalysts
N,P-doped carbon foam as an air electrode for primary and
rechargeable Zn–air batteries, published in
Nature Nanotechnology 10,444–452(2015)

Metal-free bifunctional electrocatalysts

 

Nanocomposite Materials & Thin Films
Research Pictures

Toughening mechanisms, strength, Interface phenomena, characterization of polymer, metal and ceramic matrix nanocomposites and thin films. (Read Article in Physic Review Letter)

 

Catalysts for Fuel Cells
Research Pictures

N-doped carbon nanotubes as the electrode of fuel cells, much better than platinum as catalyst for oxygen reduction. This material is promising to replace expensive platinum in fuel cells (Read Article in SCIENCEScientific Reports)

 

Bio-mimetic Materials
Research Pictures

Bio-inspired  adhesion and friction, self-cleaning and sensing,, nanotube and electro-spinning nanofiber, synthetic dry adhesives mimicking gecko footpads. Articles in SCIENCE October 2008JRS Interface 2102)

 

Sensing and Damage Detection
Research Pictures

Sensing of multifunctional materials, Damage detection in composite materials via electrical resistance, and Structural health monitoring (articles in Composites A)

 

Multiscale Modeling and Simulation

Molecular dynamics simulation of carbon nanotube pullout, buckling, adhesion and friction. (Featured cover of November 2004 issue of Materials Today)

Research Pictures

Micromechanics models for interfacial sliding and stress transfer, fracture, low-cycle fatigue crack growth in composites

Research Pictures

Meso-scale Monte Carlo Simulations of failure, fatigue crack growth, time-dependent rupture of composite materials.

Research Pictures

Cohesive-zone model for 3D crack growth in diamond thin films,TiAl3 intermetallics and nanocomposites.

Research Pictures

Large-scale finite element analysis of fracture, impact, and bird-striking.

Research Pictures

 

Recent Highlights of Our Research

Enhance Mechanical properties of carbon nanotubes with sp3bonds [article]

Damage detection of CFRP composites via electrical resistance [article]

A new method to measure fracture toughness of hard thin films [article]

Direct observation of nanotube toughening mechanisms in nanoceramic composites - a novel toughening mechanism found in the composites [article] [special report]