Research
Mechanics of conductive polymeric materials
Conductive polymers accommodates both electronic charge carriers and ions in the doped state. Their color, size, conductivity, and hardness evolves with the doping state. My research focus on the mechanical properties, deformation, stress, and degradation of conductive polymer films.
In-situ experiments
The ion/solvent insertion induces size change and mismatch strain in the conjugated polymers, eventually leading to mechanical/electrochemical/optical degradation (delamination, channel cracks, dysfunctional regions) of the polymer.
Cyclic volumetry: Real-time tracking of mechanical swelling / optical transmittance upon bias.
In-situ measurement of mechanical properties
Stress retards the electrochemical doping kinetics
Multiphysics modeling
Finite element modeling reveals the delamination mechanisms.
A continuum theory of organic mixed ionic-electronic conductors of phase separation
Mechanical deformation of a transistor interferes with the phase separation process, and changes the transfer curves (drain current against gate voltage). In the stretched case, phase separation leads to electrochemical breakdown of the transistor (diminished drain current at negative gate voltage when the transistor should actually amplify signal) due to blocked conduction path.
