Electrodeposition Characteristics of Bismuth-Telluride Films
- PDF / 100,300 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 95 Downloads / 242 Views
AA5.25.1
ELECTRODEPOSITION CHARACTERISTICS OF BISMUTH-TELLURIDE FILMS A. Prabhakar1,3, E. J. Podlaha-Murphy2,4, M.C. Murphy2,3 & R.V. Devireddy1,2,3 1 Bioengineering Laboratory, 2Center for BioModular Microsystems, 3 Department of Mechanical Engineering, 4Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA 70803. ABSTRACT This work is a part of an on-going research effort to develop an array of micro thermoelectric coolers (TECs) for highly localized control of temperature at the cellular level. Prefabrication experimentation and modeling were carried out to understand the behavior of the proposed device. Mathematical models were used to identify important device parameters and optimal device dimensions. Preliminary experiments have shown that it is feasible to produce the TECs through electrodeposition of bismuth and telluride on modules produced using a modified multistep LIGA (Lithographie, Galvanoformung and Abformung) technique. The development and characterization of the proposed TECs would enable the bioengineer highly localized control of temperature in a native or artificial tissue system. Thus enabling further usage of low temperatures in biological systems for both destructive (cryosurgical) and beneficial (cryopreservation) procedures. Keywords: Cryobiology, Intracellular ice formation, Localized temperature control, Bi-Te thermo-electric cooler
INTRODUCTION Localized control of temperature at cellular level can be achieved by fabrication of a microthermoelectric cooler (TEC). The ability to control the temperature locally promises to pave way to many new areas of applications chief amongst which are low temperature banking (storage) of tissues (artificial and native) and organs. The precise temperature control and spot cooling features of the proposed TEC device make it an ideal choice for enabling temperature modulation of individual cells embedded in an extracellular matrix. This study presents a method to fabricate an array of Peltier effect based thermoelectric (TE) modules using modified multi-step LIGA (Lithographie, Galvanoformung and Abformung) technique. The prototype device to be fabricated will consist of an array of 100 TECs that will be formed by electrodeposition of the proper materials (bismuth, Bi and telluride, Te). Within the array, the coolers will be interspersed to enable each one to be individually addressable and with each individual TEC having an n-type and p-type leg elements. These arrays of TECs will be embedded in polymethylmethacrylate (PMMA) matrix to improve insulation and will be situated under the tissue system to be cooled. PMMA sheet will provide an interface between the cooler and the embedded cells. PMMA was chosen as it is a commonly used X-Ray resist in microfabrication and is also biocompatible. In recent years, efforts to fabricate the TEC with good figure of merit have been initiated. Microfabricated structures for the leg elements based on Peltier effect were produced via LIGA technique by Huang et al [1]. Bismuth telluride alloys
Data Loading...
