@article{dong_walker_2010, title={Adjustable-Stiffness Films via Integrated Thermal Modulation}, volume={295}, ISSN={["1439-2054"]}, DOI={10.1002/mame.201000097}, abstractNote={AbstractWe present a new strategy for fabricating thermally responsive adjustable stiffness materials. A microfabricated heater embedded within a composite film is used to modulate the temperature of a low melting point polymer. Currents ranging from 0 to 200 mA were applied to the microheater and modulated material stiffness ≈100‐fold between 1.03 GPa and 10.9 MPa. The outside temperature of the composite ranged from 23 to 45.5 °C over this range of currents, suggesting its possible use in biomedical applications. The softened composite was bent into arbitrary shapes and allowed to restiffen, highlighting the reconfigurable nature of the material.magnified image
}, number={8}, journal={MACROMOLECULAR MATERIALS AND ENGINEERING}, author={Dong, Hua and Walker, Glenn M.}, year={2010}, month={Aug}, pages={735–741} }
 @article{dong_cao_li_2009, title={Functionalized Polypyrrole Film: Synthesis, Characterization, and Potential Applications in Chemical and Biological Sensors}, volume={1}, ISSN={["1944-8244"]}, DOI={10.1021/am900267e}, abstractNote={In this paper, we report the synthesis of a carboxyl-functionalized polypyrrole derivative, a poly(pyrrole-N-propanoic acid) (PPPA) film, by electrochemical polymerization, and the investigation of its basic properties via traditional characterization techniques such as confocal-Raman, FTIR, SEM, AFM, UV-vis, fluorescence microscopy, and contact-angle measurements. The experimental data show that the as-prepared PPPA film exhibits a hydrophilic nanoporous structure, abundant -COOH functional groups in the polymer backbone, and high fluorescent emission under laser excitation. On the basis of these unique properties, further experiments were conducted to demonstrate three potential applications of the PPPA film in chemical and biological sensors: a permeable and permselective membrane, a membrane with specific recognition sites for biomolecule immobilization, and a fluorescent conjugated polymer for amplification of fluorescence quenching. Specifically, the permeability and permselectivity of ion species through the PPPA film are detected by means of rotating-disk-electrode voltammetry; the specific recognition sites on the film surface are confirmed with protein immobilization, and the amplification of fluorescence quenching is measured by the addition of a quenching agent with fluorescence microscopy. The results are in good agreement with our expectations.}, number={7}, journal={ACS APPLIED MATERIALS & INTERFACES}, author={Dong, Hua and Cao, Xiaodong and Li, Chang Ming}, year={2009}, month={Jul}, pages={1599–1606} }