U.S. Patent No. 7,880,890, issued on February 1, 2011 to Block Engineering, LLC of Marlborough, MA, discloses a MEMS Michelson interferometer for Fourier transform infrared (FTIR) spectroscopy.
According to the ’890 patent, a Michelson interferometer can be used to perform Fourier transform infrared (FTIR) spectroscopy by transmitting broadband infrared light into the interferometer, modulating the path length of one of the interferometer’s arms, and irradiating the material under study with the resulting light. The inverse Fourier transform of the temporal signal from detecting the light after interacting with the material under study yields a spectrum which can be used to identify the constituents of the material. The ’890 patent discloses a microelectromechanical system (MEMS) interferometer in which the mirrors are patterned from a substrate and one or more of the mirrors is biased by a spring and locked in place.
According to its website, Block Engineering is privately-owned and its FTIR spectrometers are “installed in and around Washington, DC to protect critical infrastructure from chemical terrorist attacks.”
Its website also states that its ”patent pending MEMS miniaturization technologies are enabling breakthrough new products, like the ChemPen™, a pen-size, battery-operated FTIR sensor which can detect essentially any gas, liquid or solid.” The ChemPen™ is designed to have “small size (8 inches), low weight (8 oz), low power consumption and expected very low cost” and “is intended to detect and identify all Chemical Warfare Agents and Toxic Industrial Chemicals under field conditions” for military, homeland security, and life safety applications. Block Engineering is developing the ChemPen™ under a $4.5 million contract from the U.S. Army Research Office.
Last month, Block Engineering was awarded the Prism Award in the “Defense and Security” category at the SPIE Photonics West conference in San Francisco for its LaserScan™ high-sensitivity, mid-infrared, quantum cascade laser absorption spectroscopy system. This technology appears unrelated to the MEMS-based FTIR interferometer of the ’890 patent.
The ’890 patent is Block Engineering’s latest U.S. patent, and its first one since 1982, according to the USPTO database.
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