Testing of Milliwatt Power Source Components

A milliwatt power source (MPS) has been developed to satisfy the requirements of several potential solar system exploration missions. The MPS is a small power source consisting of three major components: a space qualified heat source (RHU), a thermopile (thermoelectric converter or TEC) and a container to direct the RHU heat to the TEC. Thermopiles from Hi-Z Technology, Inc. of San Diego and the Institute of Thermoelectricity of Chernivtsi Ukraine suitable for the MPS were tested and shown to perform as expected, producing 40 mW of power with a temperature difference of about 170°C. Such thermopiles were successfully life tested for up to a year. A MPS container designed and built by Swales Aerospace was tested with both a TEC simulator and actual TEC. The Swales unit, tested under dynamic vacuum, provided less temperature difference than anticipated, such that the TEC produced 20 mW of power with heat input equivalent to a RHU

Комп'ютерне моделювання динамічних режимів роботи термоелектричного приладу для кріодеструкції

This paper presents the results of computer simulation of optimal dynamic modes of thermoelectric device for cryodestruction. The optimal time function for controlling the supply current to thermoelectric micromodule in a device for cryodestruction is determined, which ensures given cyclic temperature effect on the local area of human body.У роботі наведено результати комп’ютерного моделювання оптимальних динамічних режимів роботитермоелектричного приладу для кріодеструкції. Визначено оптимальну часову функцію керуванняструмом живлення термоелектричного мікромодуля у приладі для кріодеструкції, якою забезпечуєтьсязаданий циклічний температурний вплив на локальну ділянку тіла людини

Unusual thermoelectric behavior of packed crystalline granular metals

Loosely packed granular materials are intensively studied nowadays. Electrical and thermal transport properties should reflect the granular structure as well as intrinsic properties. We have compacted crystalline $CaAl$ based metallic grains and studied the electrical resistivity and the thermoelectric power as a function of temperature ($T$) from 15 to 300K. Both properties show three regimes as a function of temperature. It should be pointed out : (i) The electrical resistivity continuously decreases between 15 and 235 K (ii) with various dependences, e.g. $\simeq$ $T^{-3/4}$ at low $T$, while (iii) the thermoelectric power (TEP) is positive, (iv) shows a bump near 60K, and (v) presents a rather unusual square root of temperature dependence at low temperature. It is argued that these three regimes indicate a competition between geometric and thermal processes, - for which a theory seems to be missing in the case of TEP. The microchemical analysis results are also reported indicating a complex microstructure inherent to the phase diagram peritectic intricacies of this binary alloy.Comment: to be published in J. Appl. Phys.22 pages, 8 figure

An efficient algorithm to calculate intrinsic thermoelectric parameters based on Landauer approach

The Landauer approach provides a conceptually simple way to calculate the intrinsic thermoelectric (TE) parameters of materials from the ballistic to the diffusive transport regime. This method relies on the calculation of the number of propagating modes and the scattering rate for each mode. The modes are calculated from the energy dispersion (E(k)) of the materials which require heavy computation and often supply energy relation on sparse momentum (k) grids. Here an efficient method to calculate the distribution of modes (DOM) from a given E(k) relationship is presented. The main features of this algorithm are, (i) its ability to work on sparse dispersion data, and (ii) creation of an energy grid for the DOM that is almost independent of the dispersion data therefore allowing for efficient and fast calculation of TE parameters. The inclusion of scattering effects is also straight forward. The effect of k-grid sparsity on the compute time for DOM and on the sensitivity of the calculated TE results are provided. The algorithm calculates the TE parameters within 5% accuracy when the K-grid sparsity is increased up to 60% for all the dimensions (3D, 2D and 1D). The time taken for the DOM calculation is strongly influenced by the transverse K density (K perpendicular to transport direction) but is almost independent of the transport K density (along the transport direction). The DOM and TE results from the algorithm are bench-marked with, (i) analytical calculations for parabolic bands, and (ii) realistic electronic and phonon results for $Bi_{2}Te_{3}$.Comment: 16 Figures, 3 Tables, submitted to Journal of Computational electronic

Термоелектричний прилад для контактного охолодження ока людини

The paper presents the results of the development of a thermoelectric device in the form of a monocular dressing for contact cooling of the human eye through the eyelids. The developed device allows controlled local contact cooling of the eye structures through the eyelids and is designed to treat the acute and chronic eye diseases, reduce intraocular pressure, and reduce pain and inflammatory processes of the eye. The design features of the device and its technical characteristics are presented.У роботі наведено результати розробки термоелектричного приладу у вигляді монокулярної пов’язки для контактного охолодження ока людини через повіки. Розроблений прилад дає можливість контрольованого локального контактного охолодження структур ока через повіки та призначений для лікування гострих і хронічних захворювань ока, зниження внутрішньоочного тиску, зменшення больового синдрому та запальних процесів ока. Наведено особливості конструкції приладу та його технічні характеристики

Anisotropic thermoelement in emf and current generation mode

Computer methods for the description of the anisotropic thermoelement (AT) properties with regard to all necessary model approximations have been elaborated. Configurations of eddy thermoelectric currents in the anisotropic thermoele-ment caused by current contacts have been found. The pro-perties of the AT with regard to temperature dependences of material properties, contact resistances and current contacts have been determined for concrete cases. Optimal dimensions of current contacts have been found. The optimization of AT construction allowed to increase its efficiency by 15%