A Scalable Fabrication Process for Liquid Crystal-Based Uncooled Thermal Imagers

• Published in: Journal of microelectromechanical systems Vol. 25; no. 3; pp. 479 - 488
• Main Authors: Berry, Shaun, Bozler, Carl O., Reich, Robert K., Clark, Harry R., Bos, Phillip, Finnemeyer, Valerie, McGinty, Colin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Alignment layer; Arrays; birefringence; Cavity resonators; Diamonds; Fabrication; Image detection; Infrared; Lapping; Large format; Liquid crystals; Liquids; long-wavelength infrared; microbolometers; Molybdenum; Sensors; thermal imagers; Transducers; birefringence; microbolometers; long-wavelength infrared; thermal imagers; Alignment layer; liquid crystals
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2016.2555246

A novel sensor is being developed for a new uncooled imager technology that is scalable to large formats (tens of megapixels), which is greater than what is achieved by commercial microbolometer arrays. In this novel sensor, a liquid-crystal transducer is used to change a long-wavelength infrared scene into a visible image that can be detected using a conventional visible imager. This approach has the potential for making a more flexible thermal sensor that can be optimized for a variety of applications. In this paper, we describe the microfabrication processes required to create an array of sealed thermally isolated micro-cavities filled with liquid crystals to be used for an uncooled thermal imager. Experimental results from the fabricated arrays will also be discussed.