Low‐Temperature Co‐Fired Ceramics System for Light Absorbance Measurement

Purpose – The purpose of this paper is to determine the thermoelectric properties of the germanium-based thin films and selecting the most suitable ones for fabrication of micrognerators. Design/methodology/approach – The germanium layers were deposited by low pressure magnetron sputtering method, in the pressure of 10−3/104 mbar range. The amount of dopants (germanium or vanadium) was changed in a limited extent. The influence of such changes on the layers output properties was studied. Post-processing heat treatment at temperature below 823 K was applied to activate the layers. It leads to improve the electrical and thermoelectrical performance. Findings – The special attention was paid to the power factor (PF = S2/ρ) of the layers. To estimate power factor (PF) electrical resistivity (ρ) and Seebeck coefficient (S) were determined. The achieved Seebeck coefficient value was 185 Volt/Kelvin (μV/K) for germanium doped with vanadium (Ge:V1.15) and 225 μV/K for germanium doped with gold(Ge:Au3.13) layers at room temperature. After activation process, the PF reached a value of 2.5 × 10−4 W/m · K2 for the Ge:Au3.13 and 1.1 × 10−4 W/m · K2 for the Ge:V1.15 layers. Originality/value – The fabricated thermoelectric layers can be thermally annealed in temperature up to 823 K in the air and in 1,023 K under a nitrogen atmosphere. This enables integration of thin layers with thick-film technology. Corning glass or low temperature cofired ceramic was used as a substrate.

Section: Fabrication Processmentioning

confidence: 99%

Thermoelectric properties of thin-film germanium-based layers

Markowski

Prociów

Urbaniak

2015

“…The LTCC substrate was made of DP 951 green tape. It was decided to use the LTCC technique because it is dedicated to multilayer structures fabrication (Vasudev et al, 2013;Czok et al, 2013;Malecha and Golonka, 2009), which was the objective of the work. Before the firing process, LTCC is a flexible tape (green tape), on which the thermocouple's arms can be easily performed.…”

Section: Thermoelectric Materials For the Energy Harvestermentioning

confidence: 99%

“…In Table II, parameters measured during previous research are presented. (Vasudev et al, 2013;Czok et al, 2013;Malecha and Golonka, 2009), which was the objective of the work. Before the firing process, LTCC is a flexible tape (green tape), on which the thermocouple's arms can be easily performed.…”

Section: Thermoelectric Materials For the Energy Harvestermentioning

confidence: 99%

Thermoelectric energy harvester fabricated in thick-film/LTCC technology

Markowski

2014

Purpose -The purpose of this work was fabrication of a small energy harvester. Design/methodology/approach -The multilayer thermoelectric power generator based on thick-film and low temperature co-fired ceramic (LTCC) technology was fabricated. Precise paths printing method was used to fabricate Ag/Ni and Ag/PdAg thermocouples on a number of unfired LTCC tapes. The tapes were put together to form a multilayer stack. The via holes were used to make the electrical connections between adjacent layers. Finally, the multilayer stack was fired in the appropriate thermal profile. Findings -It consists of 450 thermocouples and generates output voltage of about 0.45 V and output electrical power of about 0.13 mW when a temperature difference along the structure is 135°C. In the paper, individual stages of energy harvester fabrication process as well as its output parameters are presented. Originality/value -Miniaturized thermoelectric energy harvester based on thick-film and LTCC technology was fabricated. As materials, metal-based pastes were used. This is the first paper where multilayer thermoelectric harvester, fabricated with the aid of LTCC technology, was described.

“…Aside from that, the LTCC can also be bonded to other materials, e.g. silicon (Rusu et al, 2006), glass (Bembnowicz and Golonka, 2010;Czok et al, 2013) or polymer (Malecha et al, 2010;Malecha, 2013).…”

Section: Introductionmentioning

confidence: 99%

Technology and application of the LTCC-based microfluidic module for urea determination

Malecha

Remiszewska

Pijanowska

2015

Purpose – The purpose of this paper is to focus on the technology and performance of the miniature microfluidic module for urea determination. The presented module was made using low-temperature co-fired ceramics (LTCC). It shows the possibility for the integration of the bioreceptor layers with structures that have been fabricated using modern microelectronic technology. Design/methodology/approach – The presented microfluidic module was fabricated using LTCC technology. The possibility for the fabrication of an enzymatic microreactor in a multilayer ceramic substrate, made of CeramTec glass ceramic (GC) material systems with an integrated thick-film heater, is studied. Different configurations of the LTCC/heater materials (gold, silvers and palladium-silver) are taken into account. The performance of the LTCC-based microfluidic module with the integrated heater and immobilized enzyme was examined experimentally. Findings – A compatible material for the heater embedded in the CeramTec GC-based structures was found. The preliminary measurements made for the test solution containing various concentrations of urea have shown stability (for seven days of operation) and a relatively high signal-to-noise ratio (above 3 pH units) for the microreactor’s output signal. Research limitations/implications – The presented research is a preliminary work which is focused on the fabrication of the LTCC-based microfluidic module, with an integrated heater and immobilized enzyme for urea determination. The device was positively tested using a model reaction of the hydrolysis of urea. However, urea concentration in real (biological) fluid should also be measured. Practical implications – The development of the LTCC-based microfluidic module for urea determination provides opportunity for the construction of a lab-on-chip, or μTAS-type system, for fast medical diagnoses and the continuous monitoring of various biochemical parameters, e.g. for estimating the effectiveness of hemodialysis. Originality/value – This paper shows the design, fabrication and performance of the novel microfluidic module for urea determination, made with LTCC technology.