Fabrication and Characterization of Flexible Thermoelectric Generators Using Micromachining and Electroplating Techniques

Abstract

This study involves the fabrication and measurement of a flexible thermoelectric generator (FTG) using micromachining and electroplating processes. The area of the FTG is 46 × 17 mm2, and it is composed of 39 thermocouples in series. The thermoelectric materials that are used for the FTG are copper and nickel. The fabrication process involves patterning a silver seed layer on the polymethyl methacrylate (PMMA) substrate using a computer numerical control (CNC) micro-milling machine. Thermoelectric materials, copper and nickel, are deposited on the PMMA substrate using an electroplating process. An epoxy polymer is then coated onto the PMMA substrate. Acetone solution is then used to etch the PMMA substrate and to transfer the thermocouples to the flexible epoxy film. The FTG generates an output voltage (OV) as the thermocouples have a temperature difference (ΔT) between the cold and hot parts. The experiments show that the OV of the FTG is 4.2 mV at ΔT of 5.3 K and the output power is 429 nW at ΔT of 5.3 K. The FTG has a voltage factor of 1 μV/mm2K and a power factor of 19.5 pW/mm2K2. The FTG reaches a curvature of 20 m−1.

A low-cost and highly efficient method of reducing coolant leakage for direct metal printed injection mold with cooling channels using optimum heat treatment process procedures

“…To verify the effectiveness of the optimum HT process procedures, two sets of injection molds shown in the Figure 17 were fabricated using general process parameters. After optimum HT process procedures, post-process nishing operations of the mold injection inserts was performed for obtaining the desired dimensions of the injection mold using a computer numerical control (CNC) milling machine [26]. In addition, positioning pin holes were maching using a CNC drilling machine.…”

Foundry Service of CMOS MEMS Processes and the Case Study of the Flow Sensor

“…Figure 4a shows the deposition of the polysilicon above the substrate; Figure 4b represents the CMOS layer with an additional pattern of contact layer; Figure 4c depicts the standard CMOS layer with amorphous SiO2, metal M1-M6, metal 7 hard mask, and a passivation layer; Figure 4d developed the thick photoresist layer to perform the patterning; lastly, Figure 4e,f shows anisotropic silicon oxide etching and XeF2 isotropic silicon etching, respectively. The powerful CMOS MEMS foundry service in Taiwan has contributed to a variety of MEMS microsensor developments such as magnetic sensors [90,[98][99][100][101][102], humidity sensors [103][104][105][106][107][108], gas sensor [54,63,[109][110][111][112], pressure sensors [16,78,[113][114][115][116][117], thermoelectric energy harvesters [118][119][120][121][122], strain sensors [37,40,53], thermal sensors [123][124][125][126][127]<...…”

“…In the earlier stage, the CMOS MEMS process had a larger CD or minimum line width in the academic labs of Europe and USA [73][74][75][76][77][78][79][80]. As the CD kept on decreasing to 0.8 µm [35] The powerful CMOS MEMS foundry service in Taiwan has contributed to a variety of MEMS microsensor developments such as magnetic sensors [90,[98][99][100][101][102], humidity sensors [103][104][105][106][107][108], gas sensor [54,63,[109][110][111][112], pressure sensors [16,78,[113][114][115][116][117], thermoelectric energy harvesters [118][119][120][121][122], strain sensors [37,40,53], thermal sensors [123][124][125][126]…”

Thermoelectric Properties of a p-n Module Based on TTT2I3 and TTT(TCNQ)2 Organic Crystals

“…The thermal expansion of the lattice is considered in the coefficient β xx only for the direction of molecular chains. The expressions for output voltage and the maximum power of a pn module can be figured out as [15]:…”