Topic
Microheater
About: Microheater is a research topic. Over the lifetime, 814 publications have been published within this topic receiving 12478 citations.
Papers published on a yearly basis
Papers
More filters
••
07 Nov 2002TL;DR: In this paper, an original design of a polysilicon loop-shaped microheater on a thin stacked dielectric membrane is presented, which ensures high thermal uniformity and insulation and very low power consumption.
Abstract: In this paper, an original design of a polysilicon loop-shaped microheater on a thin stacked dielectric membrane is presented. This design ensures high thermal uniformity and insulation (20.000/spl deg/C/W) and very low power consumption (20 mW for heating at 400/spl deg/C). Moreover, the use of completely CMOS compatible TMAH-based bulk-micromachining techniques allows an easy smart gas sensor integration in SOI-CMOS technology.
14 citations
••
22 Oct 2003TL;DR: In this paper, a temperature sensor of pn junction diode and a microheater combined with a temperature-sensor was developed, which can cover very wide temperature-range of about -200 /spl deg/C to 500 /spl dc with very high sensitivity and accuracy like a NTC thermistor.
Abstract: We have developed a temperature-sensor of pn junction diode and a microheater combined with this temperature-sensor. This pn junction diode temperature sensor can cover very wide temperature-range of about -200 /spl deg/C to 500 /spl deg/C with very high sensitivity and accuracy like a NTC thermistor. We have also developed a new absolute humidity sensor using this pn diode temperature sensor combined with a microheater formed by MEMS technique. We have found from simulation of the thermal conductivity /spl lambda/ of humid air at different temperatures that thermal conductivity difference /spl Delta/ /spl lambda/ at different humid-air temperatures has a linear dependence on molar fraction of H/sub 2/O vapor. /spl Delta/ /spl lambda/ is determined from experimental data on temperatures Ta, Tb and Tc at point A (microheater point) and B (displaced point from A) on the micro-air-bridge, and at humid air, respectively. In the measurement Ta on the micro-air-bridge is periodically kept at T/sub h/ and T/sub i/ above Tc by feedback control.
14 citations
••
TL;DR: In this article, a robust silicon carbide microheater is used for stable low-power catalytic gas sensing at high operating temperatures, where previously developed low power polycrystalline silicon (polysilicon) microheaters are unstable.
Abstract: A robust silicon carbide (SiC) microheater is used for stable low-power catalytic gas sensing at high operating temperatures, where previously developed low-power polycrystalline silicon (polysilicon) microheaters are unstable. The silicon carbide microheater has low power consumption (20 mW to reach 500 °C) and exhibits an order of magnitude lower resistance drift than the polysilicon microheater after continuously heating at 500 °C for 100 h and during temperature increases up to 650 °C. With the deposition of platinum nanoparticle-loaded boron nitride aerogel, the SiC microheater-based catalytic gas sensor detects propane with excellent long-term stability while exhibiting fast response and recovery time (~1 s). The sensitivity is not affected by humidity, nor during 10% duty cycling, which yields a power consumption of only 2 mW with frequent data collection (every 2 s). With a simple change of heater material from silicon to SiC, the microheater and resulting catalytic gas sensor element show significant performance improvement.
14 citations
••
06 Dec 2011Abstract: Results from the variable gravity pool boiling experiments performed during the 52nd ESA parabolic flight campaign are reported in this paper. During a typical parabola, the gravity acceleration changes from 1.8gE (high gravity) to ~0gE (low gravity) and finally back to 1.8gE. The two high gravity periods and the microgravity period are each roughly maintained for 20 seconds while the transition from high gravity to low gravity and vice versa occurs over a period of 3–5 seconds. Use of the high feedback frequency microheater array allowed quasi-steady boiling data over the continuous range of gravity levels (0gE-1.8gE). The experimental apparatus consisted of a boiling chamber with a 7×7 mm2 microheater array in a 10×10 configuration. Each heater in the array was individually controlled to maintain a constant temperature. The array could be operated in a full configuration or a selectively powered reduced set of 3×3 heaters. Experiments were performed with FC-72 as the test fluid, the pressure was maintained at a constant value between 1 and 1.13 atm and the subcooling ranged from 27 to 11 K. An external electric field was imposed over the boiling surface by means of a grid consisting of 4 rods, laid parallel to the surface; voltages up to 10 kV were applied. The electric field was effective in reducing the size of the detaching bubbles, and increasing the heat transfer compared to the values in low-g, although its effectiveness decayed as the heat flux/superheat increased. The current results compared well with previous results obtained in the ARIEL apparatus that was operated in orbital flight.
14 citations
••
TL;DR: In this article, a low-power in-plane microheater and a temperature sensor are integrated with a low power inplane micro-heater, and analyzed by a newly developed customized sensor interface electronics to monitor the sensor's output variations in terms of relative humidity (RH) concentration.
Abstract: Reduced graphene oxide and molybdenum disulfide (rGO:MoS2) are the most representative two-dimensional materials, which are promising for a humidity sensor owing to its high surface area, a large number of active sites, and excellent mechanical flexibility. Herein, we introduced a highly sensitive and stable rGO:MoS2-based humidity sensor integrated with a low-power in-plane microheater and a temperature sensor, directly insertable to transformer insulating oil, and analyzed by a newly developed customized sensor interface electronics to monitor the sensor's output variations in terms of relative humidity (RH) concentration. rGO:MoS2 sensing materials were synthesized by simple ultrasonication without using any additives or additional heating and selectively deposited on titanium/platinum (Ti/Pt) interdigitated electrodes on a SiO2 substrate using the drop-casting method. The significant sensing capability of p-n heterojunction formation between rGO and MoS2 was observed both in the air and transformer insulating oil environment. In air testing, the sensor exhibited an immense sensitivity of 0.973 kΩ/%RH and excellent linearity of ∼0.98 with a change of humidity from 30 to 73 %RH, and a constant resistance deviation with an inaccuracy rate of 0.13% over 400 h of continual measurements. In oil, the sensor showed a high sensitivity of 1.596 kΩ/%RH and stable repeatability for an RH concentration range between 34 and 63 %RH. The obtained results via the sensor interface were very similar to those measured with a digital multimeter, denoting that our developed total sensor system is a very promising candidate for real-time monitoring of the operational status of power transformers.
13 citations