Technology

IR Sensors specialises in development and fabrication of low cost infrared (IR) sensors, primarily for the high volume Internet of Things (IoT) sensor market. The technology is based on resistance microbolometers manufactured by Micro-Electro-Mechanical Systems (MEMS) processes on silicon wafer substrates.

IR Sensors' mosaic pixel microbolometer technology was developed primarily to challenge the ubiquitous pyroelectric PIR sensors, familiar in home and industry security. Pyroelectric PIR sensors can only detect movement and are unable to identify detected targets. Microbolometer sensors can detect stationary objects, and can also determine shape, hence human presence.

Furthermore, microbolometers can detect slow temperature changes, as might be experienced with developing fire or overheating appliances.

Many other applications have been identified for this low cost IoT technology (See The Market).

Mosaic pixel technology involves interconnection of a number of functional microbolometers to create a so-called 'super pixel' at the focal plane. It is a method of producing large, highly sensitive pixels, which would otherwise be impracticable due to mechanical fragility. The large pixel size in general means short detection range, up to 50 metres for home and industry security. Human presence can be detected in typical scenarios.

Mosaic pixel technology offers exceptionally high sensitivity, which is typically expressed as Noise Equivalent Temperature Difference (NETD). Cryogenically-cooled IR photovoltaic sensors have a typical NETD of ~20mK. Commercial microbolometer sensors have an NETD of ~50mK. An imaging mosaic pixel IR sensor has an NETD of ~25mK. A non-imaging mosaic pixel sensor can have an NETD of <10mK, thus the most sensitive of all commercial IR detection technology.

Development status: IR Sensors has established a partnership with a leading pure play MEMS foundry for fabrication of patented sensor technology. Design of pilot production sensors is complete, fully integrated with the foundry capability, including wafer level vacuum packaging and through silicon vias for direct PCB mounting.

Infrared sensing and the Internet of Things: first introduced to the international IR community in a paper titled "Further applications of mosaic pixel FPA technology", Proceedings of SPIE 80123O_1 (2011).