Negative temperature coefficient (NTC) chip thermistors were thermally coupled to form a novel device (TCCT) aimed for application in microelectronics. It consists of two NTC chip thermistors Th₁ and Th₂, which are small in size (0603) and power (1/10 W). They are in thermal junction, but concurrently they are electrically isolated. The first thermistor Th₁ generates heat as a self-heating component at a constant supply voltage U (input thermistor), while the second thermistor Th₂ receives heat as a passive component (output thermistor). The temperature dependence R(T) of NTC chip thermistors was measured in the climatic test chamber, and the exponential factor B_10/30 of thermistor resistance was determined. After that, a self–heating current I₁ of the input thermistor was measured vs. supply voltage U and ambient temperature T_a as a parameter. Input resistance R₁ was determined as a ratio of U and I₁ while output thermistor resistance R₂ was measured by a multimeter concurrently with the current I₁. Temperatures T₁ and T₂ of both thermistors were determined using the Steinhart–Hart equation. Heat transfer, thermal response, stability, and inaccuracy were analyzed. The application of thermally coupled NTC chip thermistors is expected in microelectronics for the input to output electrical decoupling/thermal coupling of slow changeable signals.

A pair of thick film segmented themistors with negative temperature coefficient (NTC) were joined together (back-to-back) to form thermally coupled device (TCT). The alumina substrate enables a very high galvanic insulation of thermistors and thermal coupling at the same time. The input thermistor R ₁ in the coupled pair was self-heated at constant voltages and the output thermistor R ₂ was a heat receiver through the alumina substrate. Custom designed NTC thick film thermistor pastes were made out of nickel manganese and modified nickel manganese. Thermistor electrical resistances were measured in a climatic test chamber and the themistor exponential temperature factor B was determined for both pastes. The TCT device was electrically characterized at different ambient temperatures. The input power, heat transfer, resistance and temperature of both thermistors were measured as a function of input voltage and time. The input and output thermistor temperatures T ₁ and T ₂ were obtained using thermistor resistance and Steinhart - Hart equation.The device sensitivity and measuring inaccuracy were analyzed. The main advantage of TCT is thermal coupling / electrical decoupling. The applications of TCT device are seen in automotive electronics, home appliances and power convertors to measure output temperature vs. input power.

A pair of small disc NTC thermistors were joined together laterally using a thin layer of silicon resin between them to form a novel thermally coupled device (TCT). The epoxy coating on disc thermistors enables concurrent galvanic isolation and thermal coupling. Input thermistor Th ₁ in the coupled pair was self-heated at constant voltages and acts as heat transmitter while the output thermistor Th ₂ acted as a heat receiver through the epoxy layer and silicon resin. Small NTC disc thermistors with different nominal resistances were produced out of nickel manganese and modified nickel manganese powder. The disc thermistor resistances and the thermistor exponential temperature factor B were measured in the climatic test chamber. The input power, resistance and temperature of both disc thermistors were measured at different ambient temperatures as a function of input voltage and time. The temperature of thermistors Th ₁ and Th ₂ (input and output) was determined using the Steinhart - Hart equation. The TCT device sensitivity, stability and inaccuracy were also analyzed. The applications of disc TCT device are based on the measuring of output temperature vs. input power in automotive electronics, home appliances and power convertors.

This work presents a novel approach towards integrating electronic components with textiles, by successfully creating a fully textile-based element that is capable of detecting applied forces by variation in its resistance value. The fabrication of the device consists of a specialized siliconized conductive fabric, which is placed above and below a layer of switch fabric, which acts as a force sensor. In this paper, the effects of three different geometries are observed, as well as the washability of the device, along with tension testing. Μoreover, the device behavior is simulated as well as applied in a real-life scenario. The proposed element demonstrates a good dynamic range, high repeatability and stability, and minimal impact of washing, creating a great candidate for integration in e-textiles.

This paper presents an application of 3D printing technology for the production of a flexible inductive displacement sensor. In order to achieve wireless measurements, the sensor is designed in the form of an Archimedean spiral. An additional more complex structure consisting of two spirals was also examined. When displacement is applied to the spiral center, an increase in the distance between the adjacent turns of the spiral is achieved. As a result, there will be a decrease in inductance and a consequent change in the sensor’s self-resonant frequency. The change in resonant frequency is detected using an external coil (antenna) adapted to the sensor. The sensors are read by determining their phase-dip minimum or phase-peak maximum. This way the resonant frequency vs. displacement characteristics are obtained. The displacement measurement range is up to 30 mm. The calculated sensitivity of the proposed single and double sensor spiral systems are 1.54 MHz/mm and 0.19 MHz/mm respectively.

NTC thermistors in form of bulk ceramics and thick film, with the nominal composition \mathrm{Ni_{0.5}Cu_{0.2}Zn_{1.0}Mn_{1.3}O_4} , were prepared from fine manganite powder. The finemanganite powder with an average particle size of ~0.5 μm was obtained by calcination of homogeneous mixture of NiO, ZnO, CuO and \mathrm{Mn_2O_3} powders at 900°C for 4 h and subsequently combined planetary and agate milling. Phase composition and morphology of the manganite powder were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Disk-shaped compacts were fabricated by uniaxial pressing at 0.2GPa and sintered at temperatures between 1100 and 1250°C for 2 h. The effects of sintering temperature on density, microstructure and DC electrical resistance were evaluated. Temperature-dependent resistance measurements performed in the range from −30 to 120°C yielded a thermistor constant of B = 2352K. The energy band gap, estimated from the reflectivity knee, was 0.56 eV. Furthermore, a thick-film paste was formulated from the synthesized manganite powder and used to fabricate segmented NTC thermistors. Electrical and thermal measurements, including sheet resistance, confirmed their suitability for further sensor applications.