Searing heat in little package

Engineers have created a miniature hotplate that can reach temperatures above 1100 degrees C (2012 degrees F), self-contained within a “laboratory” no bigger than a child’s shoe.

Engineers have created a miniature hotplate that can reach temperatures above 1100°C (2012°F), self-contained within a “laboratory” no bigger than a child’s shoe.

The micro-hotplates are only a few dozen microns across, yet are capable of serving as substrates, heaters and conductors for thin-film experiments ranging from material analyses to the development of advanced sensors.

Researchers at Boston MicroSystems craft the hotplates out of silicon carbide, a robust material that can tolerate extreme heat and reach peak temperature in less than one-thousandth of a second.

Silicon carbide is not only stable at high temperatures, it is also impervious to chemical attack from most materials. As a result, the hotplates can be cleaned by burning debris off the surface.

Contained on a microchip, the tiny “labs” reside within a polycarbonate chamber that can endure near-vacuum pressures. Ports on the chamber’s sides allow gases to pass through and feed experiments, and because of the chamber’s transparency, researchers can observe experiments with a microscope as they progress.

The hotplates also contain an integrated temperature gauge and a pair of electrodes. These components allow researchers to test the electrical properties of various materials that may be deposited onto the hotplates.

Using the stable, thin-film deposition properties and integrated circuitry of the hotplates, researchers are already developing applications such as oxygen and engine emission sensors. The sensor may have several advantages over devices in today’s combustion engines, due to the micro-hotplate’s chemical stability, small size, rapid response and low power consumption.

“High-temperature silicon carbide micro-hotplates are new to the research community and may prove to be flexible tools for optics, chemical vapour deposition chambers, micro-reactors and other applications,” said Rick Mlcak, Boston MicroSystems

“The micro-hotplate arrays are versatile research tools, the same basic system can adapt to handle such diverse experiments as analyses of heat treatments and the characterisation of new thin film materials,” added Mlcak.