Microheater

About: Microheater is a research topic. Over the lifetime, 814 publications have been published within this topic receiving 12478 citations.

Design and optimization of a high temperature microheater for inkjet deposition

Abstract: Inkjet deposition has become a promising additive manufacturing technique due to its fast printing speed, scalability, wide choice of materials, and compatibility for multi-material printing. Among many different inkjet techniques, thermal inkjet, led by Hewlett-Packard and Canon, is the most successful inkjet technique that uses a microheater to produce a pressure pulse for ejecting droplets by vaporizing the ink materials in a timespan of microseconds. Thermal inkjet has been widely adopted in many commercial 3D inkjet printers (e.g., 3D Systems ProJet X60 series) due to its low cost, high resolution, and easy operation. However, the viscosity of the printable materials has been limited to less than 40 cP due to insufficient energy provided inside the nozzle to overcome the viscous dissipation of energy. This paper presents a study on the design and optimization of a high temperature microheater with a target heating temperature of more than 600 °C (compared to ~300 °C for current printhead) to increase the energy supply to the nozzle. The benefits are fourfold: (1) higher temperature will lead to faster vaporization of ink and thus higher jetting frequency and print speed, (2) higher temperature will make it possible for jetting materials with higher boiling points, (3) higher temperature will reduce the viscosity of the ink and thus the viscous dissipation of energy, and (4) higher energy supply will increase the magnitude of the pressure pulse for printing more viscous materials. In this paper, a high-temperature microheater was designed with the following objectives: to reduce thermal stress in heaters and to minimize uneven heat distribution. A literature survey was first conducted on design, fabrication, and operation of thin-film resistive microheaters. A multiphysics numerical model was then developed to simulate electrical, thermal, and mechanical responses of the microheater. The model was validated by comparison to experimental data and existing models obtained from literature. With proper parameterization of the design geometry, the geometry of the microheater is optimized using a particle swarm optimization method. Results show the optimized high-temperature microheater successfully operates at temperatures in excess of 600 °C. The design optimization enabled better characteristics for even heat distribution and minimizing stress. The design approach can serve as a fundamental means of design optimization for microheaters.

Characterization of an embedded micro-heater for gas sensors applications

Abstract: The heating characteristic of a microheater element, plated onto a thermally insulated dielectric membrane, define the sensitivity and selectivity of a micromachined gas sensor. Therefore an accurate determination of its temperature is required. In this paper, we describe a new four-point probe heating element configuration together with a simple analytical model of its thermal behavior.

Genotyping by dynamic heating of monolayered beads on a microheater surface

Abstract: This paper presents SNP scoring by DASH technology by employing dynamic heating of beads immobilized on a chip with integrated heater and sensor The microfabricated chip designed for open-surface DNA analysis allows fast, well controllable temperature ramping and homogeneous temperature distribution over the entire heater area Beads containing DNA duplexes are immobilized on the surface of the chip by microcontact printing using a PDMS stamp All three possible variants of a SNP site of an oligonucleotide were accurately scored using the bead-based DASH approach Using the chip, the total analysis time could easily be reduced by a factor 2 compared with the current DASH assay

Selective Formation of Carbon Nanotubes and Its Application to Field-Emitter Arrays

Abstract: At room-temperature ambient, carbon nanotubes (CNTs) were selectively synthesized on each bridge of the microheater array (MHA) formed on a glass substrate. Both multiwalled (MW) and single-walled CNTs could be formed by controlling the MHA temperature, which was confirmed from Raman spectroscopy. By incorporating the selectively grown MW CNTs into the lateral-gated field-emitter arrays, high current density of electron emission was observed with low device leakage.

Micro Thermoelectric Type Gas Sensor

Abstract: The present invention provides a micro thermoelectric gas sensor having a thermoelectric conversion section, a microheater, a catalyst layer formed on the microheater and to be heated by the microheater, which acts as a catalyst for catalytic combustion of a combustible gas, and a sensor detection section with an electrode pattern therefore formed on a membrane of a predetermined thickness, and a method for forming a micropattern of a functional material of a catalyst or resistor in a predetermined position on a substrate in a state in which the microstructure of the functional material remains controlled.