Theodorian Borca-Tasciuc

Theodorian Borca-Tasciuc

Professor and Associate Department Head for Graduate Affairs

Thermal and Thermoelectric Metrology, Solid-State Thermoelectric Energy Conversion, Interface and Composite Materials Conductance, Heat Conduction Fundamentals, Advanced Manufacturing of Thermoelectric Devices, Solid-State Heat Pump Systems, Solid-State Thermoelectric Energy Harvesting Systems, Thermal Energy Storage Composites and Systems

Dr. Theodorian (Theo) Borca-Tasciuc has a B.S. in Physics from Bucharest University and a Ph.D. in Mechanical Engineering from UCLA. He started his academic career in 2001 at Rensselaer Polytechnic Institute and since 2013 he is a full professor. He is the director of the Nanoscale Thermophysics and Energy Conversion Laboratory (NanoTEC) on the Rensselaer campus. His research interests include fundamental investigations of solid-state thermal transport and energy conversion and development of efficient systems for thermal management, HVAC and power generation. He received the NSF CAREER award, School of Engineering Outstanding Team award, is a member of the ASME’s K8 committee on Fundamentals of Heat Transfer, and a member of the ASME's  K-9 committee on Nanoscale Thermal Transport. He organized and chaired multiple symposia and sessions on nanoscale thermal transport and energy conversion with ASME, MRS, and CIMTEC International Conferences.

Since January 2015, Dr. T. Borca-Tasciuc serves as the Associate Department Head for Graduate Affairs and the Mechanical Engineering Program Director for the MANE Dept.

As of April 2019 Dr. T. Borca-Tasciuc graduated (as main advisor or co-advisor) 19 PhD students and 30 Master students. He authored >90 journal articles, has >5400 citations, and h-index of 37.

He is the director of a Graduate Assistance in Areas of National Need (GAANN) fellowship program, a US Dept. of Education grant which supports MANE’s new interdisciplinary Ph.D. program in aeronautical engineering and mechanical engineering.

NanoTEC Lab Research Goals

  • Discover strategies to enhance energy conversion efficiency in solid-state devices
  • Discover strategies to enhance thermal conductance of composite materials and across interfaces
  • Develop better metrology techniques for fast, accurate, and high spatial resolution characterization of thermal and thermoelectric properties of materials and their interfaces
  • Develop advanced manufacturing and testing strategies for solid-state energy conversion devices and systems
  • Develop novel solid-state heat pumps and energy conversion systems that leverage the benefits of fundamental research in new thermal and thermoelectric materials

Applications of NanoTEC Research: Solid-state refrigeration and energy harvesting, materials and devices for thermal management, novel HVAC systems, chip packaging. Licensing agreements and/or patents were awarded in the area of thermoelectric materials and high thermal conductivity composites.

Two Rensselaer student start-up companies are linked to NanoTEC research: ThermoAura Inc. and MIMiC Systems Inc. 

Student Projects: NanoTEC lab offers opportunities for a variety of hands-on, experimental, manufacturing, and simulation & design projects for graduate and undergraduate students. Email project inquiries to borcat@rpi.edu.

Research (examples)  Research focuses on experimental investigations in synergy with simulations and materials structure. Key features in 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. Non-Fourier heat conduction has critical implications 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

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 electronic, optoelectronic, and 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: 1) a scanning thermal microprobe for quantitative characterization of the thermal conductivity and Seebeck coefficient with microscale resolution; 2) a transient method for measurement of all thermoelectric properties as well as electrical and thermal contact resistances in films; 3) a photothermoelectric method to determine the anisotropic thermal conductivity and the interface thermal resistance in thin film on-substrate systems; 4) 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); 2) implementation of a novel mechanism for formation of high thermal conductivity networks in polymer composites filled with nanoparticles (patent); 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 substrate.

 

Education

BS Physics (1995), Bucharest University

PhD Mechanical Engineering (2000), University of California, Los Angeles

borcat@rpi.edu

CFES Research Area

Energy Efficiency

Selected Publications

  • For a full list of publications and citations please check: https://scholar.google.com/citations?user=lenhofkAAAAJ&hl=en Additional information please check the NanoTEC laboratory website: http://nanotec.meche.rpi.edu/
  • Novel measurement methods for thermoelectric power generator materials and devices, Patrick J Taylor, Adam Wilson, Jay R Maddux, Theodorian Borca-Tasciuc, Samuel P Moran, Eduardo Castillo, Diana Borca-Tasciuc, Innovations in Army Energy and Power Materials Technologies Vol. 36, 392, (2018).
  • Pressure-induced insulator-to-metal transitions for enhancing thermoelectric power factor in bismuth telluride-based alloys, A. Gaul, Q. Peng, D. J. Singh, G. Ramanath, and T. Borca-Tasciuc, Physical Chemistry and Chemical Physics, Vol. 19, 12784-12793, 2017.
  • Thermal conductivity measurements of high and low thermal conductivity films using a scanning hot probe method in the 3ω mode and novel calibration strategies, A. A. Wilson, M. Muñoz Rojo, Begoña Abad, J. Andrés Perez, J. Maiz, J. Schomacker, M. Martín-Gonzalez, D.-A. Borca-Tasciuc and T. Borca-Tasciuc, Nanoscale, Vol. 7, 15404-15412, 2015.
  • Self-Constructed Tree-Shape High Thermal Conductivity Nanosilver Networks in Epoxy, K. Pashayi, H. R. Fard, F. Lai, S. Iruvanti, J. Plawsky and T. Borca-Tasciuc, Nanoscale, Vol. 6, 4292-4296, 2014.
  • Scanning Probe Methods for Thermal and Thermoelectric Property Measurements, T. Borca-Tasciuc, for the volume Experimental Techniques for Micro/Nanoscale Thermal and Thermoelectric Measurements, Annual Reviews of Heat Transfer, Vol. 16, 211-258, Invited Article, 2013.
  • 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.
  • 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.
  • 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.
  • Novel Measurement Methods for Thermoelectric Power Generator Materials and Devices, P. J. Taylor, A. A. Wilson, J. R. Maddux, T. Borca-Tasciuc, S. P. Moran, E. Castillo, D.-A. Borca-Tasciuc, in Thermoelectrics for Power Generation - A Look at Trends in the Technology, editors Sergey Skipidarov and Mikhail Nikitin, InTech Publishing, Rijeka, Croatia, 2016.
  • 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.
  • 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.