Development of planar micro generator using thick-film thermoelectric materials

• Main Author: 莊宗奇
• Other Authors: 楊啟榮
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/42584123982277584188

碩士 === 國立臺灣師範大學 === 機電科技研究所 === 100 === In view of the oil reserves are depleting, and greenhouse gas emissions blamed for global warming, the world is increasing emphasis on renewable energy research. Thermoelectric materials have the characteristics of heat, and electrical conversion that can use for the power generation or cooling. The thermoelectric micro power generation component has a small, non-polluting, high life, and easy integration with IC components. The thermoelectric power generation technology has been application of various fields in foreign countries. Because of screen-printing has ability in once printing process to product the functional thick-film, so that is beneficial to achieve rapid product, and mass production. Therefore, this study will use of precision screen printing technology to replace traditional fabrication of thermoelectric devices. Trying to use the SU-8 negative photoresist as an organic adhesive, and add conductive polymer Eeonomer R300F in organic adhesive to improve the conductivity. Producing a thick-film planar thermoelectric power generator that to meet green energy requirement. The study results show that organic adhesive of SU-8 photoresist mixing Eeonomer R300F has been successfully developed, and add Sb2Te3 p-type or n-type Bi2Te3 thermoelectric powder, made into a printable thermoelectric inks. In addition, mix Ethyl-cellulose, Alpha-terpineol, and Sb2Te3 or Bi2Te3 to making Ethyl-cellulose, EC version thermoelectric ink. In different annealing conditions, explore two different types of organic adhesives. The SU-8 version thermoelectric materials in the annealing conditions of 290 oC, and 12 hours, Seebeck coefficient of Sb2Te3 and Bi2Te3 are 24.99 uV/K, and -54.52 uV/K, conductivity are 27.47 S/m, and 16.72 S/m. When the annealing temperature rise to 500 oC, Seebeck coefficient changed to 42.25 uV/K, and -21.45 uV/K, conductivity increased to 60.98 S/m, and 32.05 S/m. EC version thermoelectric materials, in the annealing conditions of 500 oC, and 2 hours, Seebeck coefficient, and conductivity of Sb2Te3, and Bi2Te3 were 106.86 uV/K, -79.17 uV/K; 82.64 x10^2 S/m, and 84.75 x10^2 S/m. Then we use screen printing technology, with the proportion of thermoelectric ink, and annealing parameters, to printing the planar thermoelectric generator. The linewidth of silver electrode is 500 um, and thickness is 41.74 um. The linewidth of thermoelectric structure is designed for 250~1000 um, thickness of SU-8 version p-type, and n-type thermoelectric structures are 28.07 um, and 45.65 um, respectively. The thickness of EC version p-type, and n-type thermoelectric structures are 37.54 um, and 26.01 um, respectively. The results show the design of 500 um in linewidth, 10 mm in length, and 30 pairs in thermocouples have maximum output voltage. When a temperature difference of 40 K, the SU-8 version thermoelectric device with 290 oC, and 12 hr annealing has 26.3 mV output voltages, annealing conditions of 500 oC, and 12 hr can get output voltage of 60.4 mV. The EC version thermoelectric devices with 500 oC, and 2 hr annealing can get 196.6 mV output voltages. Then we use multi-layer stacking process, to complete the SU-8 version 3D multi-layer planar thermoelectric generator, and measure its output characteristics. The measurement results show that thermoelectric modules of 3-layers stacked, about 2.6 times of voltage output, and 5.8 times of power output compared with single. When a temperature difference of 40 K, the thermoelectric module has 156.7 mV output voltage, and 88.635 uW output power can be obtained.