Showing papers on "Microheater published in 1997"
TL;DR: In this article, the authors modeled the heating performance of a silicon micromachined microheater and discussed the pros and cons of the use of stacked dielectric membranes instead of p ++ -Si membranes.
Abstract: In this paper, we model first the heating performance of a silicon micromachined microheater. The pros and cons of the use of a stacked dielectric membranes instead of p ++ -Si membranes are discussed, either in terms of electrical consumption, or in terms of emperature homogeneity. Then, we realize and characterize two examples among the simulated structures. This allows some practical problems during the fabrication, essentially due to mechanical breakdown, to be demonstrated. A general agreement between results is found. This study shows significant promise in the development of stacked dielectric membranes.
58 citations
TL;DR: A microheater structure and its integration on a silicon microprobe, which can be used to heat local areas of tissue or to measure local tissue temperature with an accuracy of <0.3/spl deg/C, is described.
Abstract: This paper describes a microheater structure and its integration on a silicon microprobe. The 30-/spl mu/m-diameter microstructure can be used to heat local areas of tissue or to measure local tissue temperature with an accuracy of <0.3/spl deg/C. The polysilicon microheater is suspended on a dielectric membrane to reduce undesired heat conduction to the probe substrate. The heating efficiency is 4.4/spl deg/C/mW in still water and 2.2/spl deg/C/mW in guinea pig cortex. Six milliwatts applied for 2 min in cortex produces a temperature of 50/spl deg/C, creating a well-defined 50-/spl mu/m-wide lesion for determining probe position histologically. Fabrication of the heaters requires no additional masking or processing steps in addition to those normally used for recording or stimulating probes.
24 citations
TL;DR: In this paper, the Pd tunnel diode was operated at elevated temperatures, resulting in a marked reduction of the response time, less than 1 min at 83°C, and a microheater attached to the back surface of the substrate could be an efficient power source to heat the hydrogen sensor to the required temperature.
Abstract: An Al–Al2O3–Pd tunnel diode acts as a sensitive hydrogen gas sensor. A serious drawback, however, of this hydrogen gas sensor operating at room temperature was a very long response time, typically 30 min. To overcome this disadvantage, the Pd tunnel diode was operated at elevated temperatures, resulting in a marked reduction of the response time, less than 1 min at 83°C. A microheater attached to the back surface of the substrate could be an efficient power source to heat the hydrogen sensor to the required temperature.
9 citations
TL;DR: In this paper, a miniaturized 1.55 μm tunable fiber Bragg grating (FGB) filter is proposed and successfully demonstrated using an aluminum ceramic-tube with a tungsten thick film sleeve microheater.
Abstract: A miniaturized 1.55 μm tunable fiber Bragg grating (FGB) filter is proposed and successfully demonstrated using an aluminum ceramic-tube with a tungsten thick film sleeve microheater. Fine tuning of the Bragg reflective wavelength with 0.0135 nm/oC is achieved by adding the constant thermal distribution along the uniform FBG with a 0.3 nm bandwidth. Furthermore, a 1.5 nm linearly chirped reflection bandwidth is obtained by thermal gradient loading.
7 citations
Patent•
20 Feb 1997
TL;DR: In this article, a very small heater, which heats a semiconductor laser and has a function to make its oscillation wavelength variable, is formed directly on a side facing the microheater on a substrate.
Abstract: PROBLEM TO BE SOLVED: To easily control the oscillation wavelength of a semiconductor laser device by a method wherein a very small heater, which heats a semiconductor laser and has a function to make its oscillation wavelength variable, is formed directly on a side facing the semiconductor laser on a substrate. SOLUTION: An SiO2 film 102 is formed on an Si substrate 101 by using a thermal CVD method, and a metal thin film is formed by a sputtering operation. Then, the metal thin film is patterned by a photolithographic operation and an etching operation, and a microheater 103 as a very small heater, bonding pads 104 and lead wires 105 which connect both are formed. Then, when a semiconductor laser 301 is mounted on the substrate 101, it is formed directly on the Si substrate 101 facing the microheater 103. Thereby, the oscillation wavelength of a semiconductor laser device can be controlled by using the microheater 103 in an easy process and by an interconnection.
7 citations
Patent•
07 Oct 1997
TL;DR: In this article, a microheater which facilitates volume production with a higher thermal insulation and a limited power consumption and a CO sensor which enables production at a lower cost with easier volume production is provided.
Abstract: PROBLEM TO BE SOLVED: To provide a microheater which facilitates volume production with a higher thermal insulation and a limited power consumption and a CO sensor which enables production at a lower cost with easier volume production in addition to a higher detection speed, a higher detection accuracy and a limited power consumption. SOLUTION: Heaters 6 and 7 are formed on insulating diaphragms 13a and 13b to reduce the thermal capacity and through holes 14a and 14b are arranged in the perimeter of the heaters 6 and 7 to enhance the thermal insulation. As a result, it is possible to reduce power consumption with a smaller capacity of heat while shortening the measuring cycle and further to improve measuring accuracy. Both the heaters 6 and 7 are arranged thermally insulated on the same substrate 1. Thus, the concentration of CO can be detected with the temperature compensated for by checking changes in resistance values of both the heaters 6 and 7 with a bridge circuit thereby achieving a quick and accurate detection of the concentration of CO.
4 citations
TL;DR: In this article, an infrared light source made of a heavily doped single crystal silicon microbridge was developed, which was formed by boron ion implantation and ammonia anisotropic etching.
Abstract: We have developed an infrared light source made of a heavily doped single crystal silicon microbridge. This microbridge was formed by boron ion implantation and ammonia anisotropic etching. This infrared light source comprises a microheater. Accordingly infrared light is radiated from the heated microbridge. Because the ion implantation is possible to form a very thin layer of heavily doped single crystal silicon, the microheater has very small heat capacity. The size of the microheater is about 650×200×1.5μm3. It had a peak of radiant intensity at 4μm wavelength. Only 150mW drive power was consumed to raise the temperature of the microheater to 780°C. It had a small thermal time constant less than lmsec, and wide modulated temperature more than 700°C at 100Hz. Therefore, the infrared light source can radiate intermittent infrared light with direct electrical power drive. There is possibility that handy infrared sensing systems are realized.
2 citations
14 Jul 1997
TL;DR: In this article, an ONU was constructed using a low cost WDM splitter by electrically enhancing the isolation between digital and video signals, thus establishing further feasibility for a low-cost consumer ONU.
Abstract: nal. In our system with an enhanced digital RX module, even when the optical power of the video signal (Pvo) at point T (carrier frequency f,,‘ > 91 MHz, degree of modulation = 50%) was +1 dBm, no digital RX sensitivity penalty was observed. Let’s discuss the interference of the digital signal leaked into the video line on the video signal. Assuming that the optical power of the digital signal (Pdo) at Point T is -14 dBm/Ave, the intensity of the digital signal leaked into the video line (Pdv) is -35 dBm/Ave (Is of 20 dB is assumed), which is far lower than the sensitivity of a wide band analog video receiver. In our system an analog video receiver with a 2.5 GHz bandwidth and sensitivity of -25 dBm/Ave was used. No interference of the digital signal on the video quality was visually observed. In conclusion, we have successfully demonstrated that an ONU can be constructed using a low cost WDM splitter by electrically enhancing the isolation between digital and video signals, thus establishing further feasibility for a lowcost consumer ONU.
2 citations
Patent•
19 Aug 1997
TL;DR: In this article, the authors used a metal having a performance for decomposing hydrogen or hydrogen compound as a gate electrode to control catalytic activity according to temperature by using a metal which was extended and guided onto a microheater.
Abstract: PROBLEM TO BE SOLVED: To control catalytic activity according to temperature by using a metal having a performance for decomposing hydrogen or hydrogen compound as a gate electrode. SOLUTION: The thin film of a metal which is a gate electrode 1 is extended and guided onto a microheater 2. On the exposed surface of the electrode 1 extended part formed of the metal in a high temperature part where the heater 2 is present, hydrogen molecule (H2 )or hydrogen compound is decomposed, and the dissociated hydrogen is difused in the electrode 1 to form an electric double layer on the critical surface with a gate insulating film 3 of SiO2 . Thus, the current carried between a source and a drain is modulated, and taken out as a detection signal. A thin diaphragm 5 of SiO2 supported only in the peripheral part can be formed on a silicon base 4, and the heater 2 is arranged thereon, whereby a thermally insulated local high temperature part in which the heat transfer to a FET part is prevented can be formed. A highly sensitive FET sensor capable of controlling the catalytic activity by temperature can be realized.
2 citations
14 Nov 1997
TL;DR: In this article, a microheater-based sensor for thermal analysis was fabricated using micromachining technique and its characteristics were obtained. But the authors did not consider the effect of evaporation heat on the accuracy of the measurements.
Abstract: Miniaturized sensor for thermal analysis is fabricated using micromachining technique and its fundament al characteristics are obtained. This device fabricated in a Si substrate consists of monolithically integrated components of an air-bridge type microheater, a thin film thermocouple and a sample-holder. Boiling points of liquid samples, water and methanol, are observed in the heating curve and the heating-rate curve, and sudden decrease of the temperature at the dropping time of the liquid samples at room temperature due to the effect of evaporation heat is also observed. Loss of the sample due to the evaporation during heating was theoretically discussed.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.