thermal metrology

Theodorian Borca-Tasciuc

Wed, 2010-10-13 12:25 — borcat

Name:	Theodorian Borca-Tasciuc
Title:	Professor
Department	Mechanical Aerospace and Nuclear Engineering
School	Engineering
Center	Center for Automation Technologies and Systems (CATS) Center for Future Energy Systems (CFES) Center for Integrated Electronics (CIE) Rensselaer Nanotechnology Center (RNC) Smart Lighting Engineering Research Center (ERC)
Website:	http://nanotec.meche.rpi.edu/

Bio Upon graduating from Bucharest University, Theodorian Borca-Tasciuc spent several months as a research assistant for The Institute of Physics and Technology of Radiation Devices, also located in Bucharest. He joined Duke University's Department of Mechanical Engineering and Materials Science for over a year as a graduate student research assistant before beginning work on his doctorate at UCLA (PhD 2000).

Dr. Theodorian Borca-Tasciuc has started his academic career in 2001 at Rensselaer Polytechnic Institute and since 2007 he is an associate professor. He is the director of the Nanoscale Thermophysics and Energy Conversion Laboratory (NanoTEC) on the Rensselaer campus. He received the NSF CAREER award (2004), is an associate editor for the Journal of Nanomaterials, and a member of the ASME’s K8 committee on Fundamentals of Heat Transfer. He has organized and chaired symposia and sessions on nanoscale thermal transport and energy conversion with ASME and MRS.

Research Description

The main research theme in the Nanoscale Thermophysics and Energy Conversion(NanoTEC) laboratory directed by Dr. Theodorian Borca-Tasciuc is engineering nanoscale thermal transport and thermoelectric energy conversion. His work focuses on experimental investigations in synergy with physical models and materials structure. Features in the investigated samples (thin films, nanoparticles, nanowires, or the nano-domains in nanomaterials) are typically smaller than characteristic length scales of the heat carriers (such as the carrier mean free path), so conduction of heat can strongly deviate from the classical Fourier law. Similarly, nanoscale heat sources could also exhibit non-classical conduction of heat. These are critical issues for the thermal management of nanodevices, nanointerconnects, optoelectronics, or the design of nanocomposites and nanomaterials.
On another hand, nanostructures and nanostructured materials enable novel ways to independently control the thermoelectric properties (Seebeck coefficient and electrical and thermal conductivities) that define the thermoelectric figure of merit Z, a metric important for thermoelectric energy conversion applications ( such as solid state refrigeration and power generation). The enhancement of Z in nanostructures is mainly effected through control of size, interfaces, and doping in the material. The goal is to obtain non-dimensional figures of merit (ZT, T is temperature) that increase to values as high as 1.5-3, from the current values <1, to revolutionize solid state thermoelectric applications for cooling and power generation from waste heat.

Understanding and engineering the thermal and thermoelectric transport at nanoscale is therefore an essential and challenging part of Dr. T. Borca-Tasciuc’s research. A critical role is played by development of experimental techniques able to probe transport properties at nanoscale, in nanomaterials, across-nanointerfaces, or to test the operation of nanoscale thermoelectric devices. These techniques are employed to perform studies of property-structure relationship to understand and optimize thermal and thermoelectric transport as required by specific applications. Selected examples of techniques developed include a scanning thermal microprobe for quantitative characterization of the thermal conductivity and Seebeck coefficient with microscale resolution, a transient method for measurement of all thermoelectric properties as well as electrical and thermal contact resistances in films, a photothermoelectric method to determine the anisotropic thermal conductivity and the interface thermal resistance in thin film on-substrate systems, a Joule heating thermometry method for characterization of thermal transport from nanoscale heat sources.

Selected investigations include: 1) discovery of a new class of highly scalable, high figure of merit, nanostructured bulk thermoelectric materials (patent pending); 2) implementation of a novel mechanism for formation of high thermal conductivity networks in polymer composites filled with nanoparticles (patent pending); 3)investigations of anisotropic thermal properties in aligned carbon nanotube arrays and aligned carbon-nanotube polymer composites; 4) studies of the interface thermal resistance at the native interface between carbon nanotube arrays and the silicon substrate; 5) investigations of thermal transport in Si/Ge and Si/SiC multilayers; 6) investigations of non-Fourier thermal transport from individual nanoscale heaters to silicon substrates;

Details

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Keywords

Education Ph.D. University of California, Los Angeles

Scholarly Works:

This is a list of selected works. For a full list of publications and additional information please check the NanoTEC laboratory website:http://nanotec.meche.rpi.edu/
A New Class of Doped Nanobulk High-Figure-of-Merit Thermoelectrics by Scalable Bottom-up Assembly, R. J. Mehta, Y. Zhang, C. Karthik, B. Singh, R. W. Siegel, T. Borca-Tasciuc & G. Ramanath, Nature Materials, Vol. 11, 233-240, 2012.
Enhanced Thermal Conductivity in a Nanostructured Phase Change Composite due to Low Concentration Graphene Additives, F.Yavari, H. Raeisi Fard, K. Pashayi, M. A. Rafiee, A. Zamiri, Z. Yu, R. Ozisik, T. Borca-Tasciuc and N. Koratkar, J. Phys. Chem. C, Vol. 115, 8753, 2011.
A non-contact thermal microprobe for local thermal conductivity measurement, Y. Zhang, E. Castillo, R. Mehta, G. Ramanath, and T. Borca-Tasciuc, Review of Scientific Instruments, Vol. 82, 024902, 2011.
Thermoelectric characterization by transient Harman method under non-ideal contact and boundary conditions, E. E. Castillo, C. L. Hapenciuc, and T. Borca-Tasciuc, Review of Scientific instruments, Vol. 81, 044902, 2010.
A microprobe technique for simultaneously measuring thermal conductivity and Seebeck coefficient of thin films, Y. Zhang, C. L. Hapenciuc, E. E. Castillo, T. Borca-Tasciuc, R. J. Mehta, C. Karthik, and G. Ramanath, plied Physics Letters, Vol. 96, 062107, 2010.
Temperature dependent thermal conductivity of Si/SiC amorphous multilayer films, M. Mazumder, T. Borca-Tasciuc, S. Teehan, H. Efstathiadis, E. Stinzianni, and V. Solovyov, Applied Physics Letters, Vol. 96, 093103, 2010.
Effect of Nanoparticles on the Liquid-Gas Surface Tension of Bi2Te3 Nanofluids, S. Vafaei, A. Purkayastha, A. Jain, G. Ramanath and T. Borca-Tasciuc, Nanotechnology, Vol. 20, 1855702, 2009.
Thermal resistance of the native interface between vertically aligned multiwalled carbon nanotube arrays and their SiO2/Si substrate, Y. Son, S. K. Pal,T. Borca-Tasciuc, P. M. Ajayan, R. W. Siegel, Journal of Applied Physics, Vol. 103, 024911, 2008.
Electrowetting on dielectric-actuation of microdroplets of aqueous bismuth telluride nanoparticle suspensions, Raj K Dash, T Borca-Tasciuc, A Purkayastha and G Ramanath, Nanotechnology, Vol. 18, 475711, 2007.
Effect of nanoparticles on sessile droplet contact angle, Vafaei, S., Borca-Tasciuc, T., Podowski, M. Z., Purkayastha, A., Ramanath, G., and Ajayan, P. M., Nanotechnology, Vol. 17, 2523-2527, 2006.
Anisotropic Thermal Diffusivity of aligned multiwall carbon nanotube arrays, Borca-Tasciuc, T., Vafae, S., Borca-Tasciuc, D.-A., Wei, B. Q, Vajtai, R., and Ajayan, P., Journal of Applied Physics, Vol. 98, 054309, 2005.
Data Reduction in 3w Method for Thin-Film Thermal Conductivity Determination, Borca-Tasciuc, T., Kumar, A. R., and Chen, G., Review of Scientific Instruments, Vol. 72, 2139-2147, 2001.
Thermal Conductivity of Symmetrically Strained Si/Ge Superlattices, Borca-Tasciuc, T., Liu, W. L., Liu, J. L., Zeng, T., Song, D. W., Moore, C. D., Chen, G., Wang, K. L., Goorsky, M. S., Radetic, T., Gronsky, R., Sun, X., and Dresselhauss, M. S., Superlattices and Microstructures, Vol. 28, 199-206, 2000.
Thin-film Thermophysical Property Characterization by Scanning Laser Thermoelectric Microscope,Borca-Tasciuc, T. and Chen, G., International Journal of Thermophysics, Vol. 19, 557-567, 1998.