Srikar Vengallatore

Research Interests

Primary Research Theme: Materials and Structures
Secondary Research Theme: Design and Manufacturing

Microsystems and nanosystems (MEMS/NEMS) are miniaturized engineering devices that are manufactured using micrometer- and nanometer-scale structural components. These small systems are being developed for a staggering array of applications that range from sensing and displays to portable power generation and medical diagnostics. My research interests reside at the intersection of three fields: MEMS/NEMS, Energy, and Materials Science. Our research activities focus on two main thrust areas. The first is energy dissipation and structural damping in micro/nanomechanical resonators. Using both theory and experiments, we study thermoelastic damping in micromachined structures and internal friction in thin films. The results emerging from these studies are used to formulate scale-dependent process-structure-property relationships to guide the design of resonant microsensors. The second thrust area focuses on the design and prototyping of MEMS for energy harvesting and energy storage. We are currently developing advanced materials and processes for piezoelectric vibration energy harvesters and a Rankine micro-engine for harvesting waste heat.

Current Research Projects

• Theoretical studies of thermoelastic damping in micromechanical resonators with complex geometries and composite architectures.
• Experimental and theoretical studies of internal friction in ultrathin films of metals and ceramics.
• Experimental and theoretical studies of the dynamics of microcantilevers containing flow.
• Design and prototyping MEMS-based Rankine engines for energy harvesting.
• Design and prototyping of piezoelectric vibration energy harvesters for portable applications.
• Developing approaches for integrating nanomaterials with micromachined structures to enhance the functionality and performance of MEMS.

Most Significant Publications

• S. Prabhakar and S. Vengallatore, "Thermoelastic damping in micromechanical beam resonators with two-dimensional heat conduction," IEEE/ASME Journal of Microelectromechanical Systems, vol. 17, pp. 494-502 (2008)
• S. Vengallatore, "Analysis of thermoelastic damping in laminated composite micromechanical beam resonators," Journal of Micromechanics and Microengineering, vol. 15, pp. 2398 – 2404 (2005)
• M. Kuhn, T. Napporn, M. Meunier, S. Vengallatore and D. Therriault, "Miniaturization Limits for single-chamber micro-solid oxide fuel cells with coplanar electrodes," Journal of Power Sources, vol. 194, pp. 941-949 (2009)
• M. Liamini, H. Shahriar, S. Vengallatore and L. Frechette, "Design methodology for a Rankine microturbine: thermomechanical analysis and materials selection," IEEE/ASME Journal of Microelectromechanical Systems (in press, 2010)
• S. Vengallatore, "Gorsky damping in nanomechanical structures," Scripta Materialia, vol. 52, pp. 1265 – 1268 (2005)

Courses