My research interest lies in chemical sensing and the challenges in creating a sensitive, selective, and stable sensor. My initial project investigated the use of gold nanoparticle-decorated graphene for the electrochemical detection of sulfide ions in aqueous media. Single-layer graphene is grown via chemical vapor deposition on copper foil and decorated with gold through galvanic displacement. The gold-decorated graphene is transferred to an inert substrate for electrochemical testing. Characterization is done with Raman spectroscopy, SEM, AFM, and XPS.
My current focus is on the development of low power microheater-based combustible gas sensing. Using novel catalyst materials like Pt or Pd nanoparticle-loaded graphene aerogels and Pt nanoparticle-loaded boron-nitride aerogels, we have shown good performance for hydrogen and propane gas detection. A doped polysilicon microheater is encapsulated in a silicon nitride membrane and can reach 350 C with a power of only 10 mW. Catalyst material is then deposited from solution. When the combustible gas contacts the heated catalyst, exothermic reaction releases heat, which increase the temperature of the micro heater and changes the resistance of the polysilicon.
A. Harley-Trochimczyk, J. Chang, Q. Zhou, J. Dong, T. Pham, M. Worsley, R. Maboudian, A. Zettl, W. Mickelson, "Catalytic hydrogen sensing using microheated platinum nanoparticle-loaded graphene aerogel", Sensors and Actuators B: Chemical 206, 399-406 (2015).
A. Harley-Trochimczyk, J. Chang, T. Pham, J. Dong, M. A. Worsley, A. Zettl, W. Mickelson, R. Maboudian, "Low power microheater-based combustible gas sensor with graphene aerogel catalyst support", Proceedings of the 18th International Conference on Solid-State Sensors and Actuators, Transducers '15, pp. 1483-1486 (2015).
A. Harley-Trochimczyk, T. Pham, J. Chang, E. Chen, M.A. Worsley, A. Zettl, W. Mickelson, R. Maboudian, "Platinum nanoparticle-loading of boron nitride aerogel and its use as a novel material for low power catalytic gas sensing," Advanced Functional Materials, (under review).
T. Pham, A. P. Goldstein, A. Harley-Trochimczyk, A. Yan, J. P. Lewicki, W. Mickelson, A. Zettl, and M.A. Worsley, "Aerogels Based on 2D Materials," Materials Research Society, Spring 2015.
National Science Foundation Graduate Research Fellowship, (2012).
Dow Excellence in Teaching Award, (2013).
Entrepreneurial Lead, National Science Foundation Innovation Corps Program, (2013).
Best Presentation at the Berkeley Science and Actuator Center Industry Advisory Board review, (2015).
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