August 21, 2019 by Luke James
Mitsubishi recently announced on its website that it had released a thermal diode infrared sensor. It can distinguish between human beings and other heat sources by detecting movement such as walking or running.
The sensor, MelDIR—which stands for Mitsubishi Electric Diode InfraRed—launches on November 1st and is designed for applications across several fields, including heating, ventilation, HVAC, and smart buildings. It delivers high-pixel, high-resolution images using proprietary thermal diode infrared sensd goor technology.
The MelDIR is built on a thermal diode infrared sensor, the technology for which Mitsubishi developed specifically for DAICHI-2, the Advanced Land Observing Satellite-2. It is designed for security and smart building applications due to its high 80x32 pixel count.
When compared with today's thermopile sensors with a pixel count of only 16x16, the MelDIR offers up to 10 times higher pixel resolution and five times higher thermal resolution at 0.1 degrees Celsius. The sensor's supporting legs, made thin using microfabrication, facilitate energy flow while not releasing heat. This allows more pixels to be used for higher resolution.
The MeDIR sensor. Image courtesy of Mitsubishi.
The result is a sensor that enables highly detailed thermal images and the ability of it to distinguish between human and other heat sources, and for the identification of human behaviours such as running, walking, and jumping.
Using Mitsubishi's new packaging technology, the overall module size is 80% smaller than that of the average existing sensor. This allows for more discreet deployment in security applications.
While the MelDIR has potential applications to a huge number of projects, the more obvious application is in smart buildings for security purposes.
Since the sensor can distinguish between human and other heat sources with a high degree of accuracy, it is perfect for use in security systems that currently utilize sensors for the tripping of alarms, etc. For instance, MelDIR, when used as part of an alarm system, could be used to detect animal movement—say that of a dog—and distinguish it from that of a human being to prevent a false alarm.
The MelDIR comes only five months after the launch of what Mitsubishi claimed to be an infrared sensor with the "world's highest sensitivity".
In March, the company debuted its MWIR and LWIR graphene-based sensors that boasted a sensitivity more than 10 times higher than that of quantum-type infrared sensors. To do this, Mitsubishi utilized graphene's high electron mobility.
