New Sensor Technology Can Allow for Smarter Presence Detection

Small, inexpensive, battery-powered and IoT-caged sensors can be quickly connected with the help of 5G networks to bring about new and more efficient presence detection in, for example, the construction and real-estate sectors.
Published: April 14, 2019

A rapid technological development within the Internet of Things (IoT) means that more and more things in our everyday life can be connected. The connection is made with the help of a gateway or a hub, which can collect data from a large number of sensors, which it then forwards to the cloud via, for example, 5G.

The IoT and sensors will be each other’s preconditions in a variety of technical solution areas in this connected world. One such area is smart homes and buildings. Here, the development is very fast, ranging from older sensors that control a relay that turns on and off a lightning system, to a whole new generation of sensors that can send data to just a single gateway, which in turn controls the lamp exactly the way you want.

Today’s Pyroelectric Sensors Provide Limited Presence Detection
Most sensor systems currently used for presence detection are built with pyroelectric sensors. But their properties are limited and they can only sense changes in temperature, making them less suitable for areas in which a user is expected to remain, for example, in a room or in front of a computer. A new type of sensor, on the other hand, could detect human presence by monitoring for heat radiation. In this way, it would be much better at detecting immobile people in a room or office space, or in front of a unit, such as a computer or a tablet.

Improved Thermopile Sensors Are Important for Smarter Presence Detection
So how are such sensors constructed? A new generation of presence detection is equipped with a so-called thermopile, which is manufactured using nanotechnology. A thermopile is a series of connected thermocouples that can convert thermal (heat) energy into electrical energy. Thermopiles can be used to measure absolute or relative temperature and heat flow. This, in turn, can detect, for example, movement or presence. Moreover, they are passive and do not consume any energy when not measuring.

Several New Applications Within Construction and Property Save Energy and Increase Safety
Common areas of use include smoke and gas detection, movement, absolute temperature measurements, heat measurement and the control of heat-sensitive parts and plumbing. Other areas include smart offices or public spaces such as libraries, for instance, to determine whether or not a place is vacant. By using a sensor to wake a device only if someone is present, you can reduce energy consumption and thus extend battery life. Such sensors could also potentially be used to activate biometric authentication systems, such as fingerprint scanning or facial and iris recognition, which consume a lot of energy when active.

Nanotechnology Makes Sensors Thin, Flexible and Cost-Effective
This new type of sensor is based on nanotechnology, which offers a lot of advantages. It measures only 0.17 millimeter in thickness and is almost entirely composed of plastic. The plastic piece is very robust and could be used without the metal housing, or protective cover, which is often utilized on conventional sensors. In addition to being thin and robust, the sensor is also flexible, but is cost-effective to produce in large volumes. This makes it suitable for all types of applications that require small sensors when temperature or heat flow should be measured.

Anders Jansson is the CTO at Swedish IR sensor manufacturer JonDeTech Sensors AB.