IoT sensors are the starting point of the IoT value chain. They are the source of the data which is the core of every IoT initiative. Every IoT application depends on the accurate and on-time delivery of relevant data sets. On the other hand, the actuator (or counterpart of the sensor), has the job to put the outcome of the big data Analysis into Action. So neither sensors nor actuators are a mere commodity that merely measure always the same data stream or execute simple Tasks. They are the centrepieces of every smoothly working IoT service structure.
IoT sensors and actuators untangled
Sensors measure physical facts like temperature, speed or pressure. They convert the physical facts into electrical impulses and send them in defined intervals to a control centre where the data is further processed. Actuators however do the exact opposite. They receive orders from the control center, where the data was analysed in order to come to a conclusion how the IoT device should react. The actuatur is transforming the electric impulses into physical Actions.
Relationship Sensor – Control Center – Actuator
Source: A reference guide to IoT, Bridgera
There are several types of sensors, all serving a different and distinct purpose. Some measure speed, some temperature. There are sensors that can detect and specify acoustic signals or gases. Others gauge load or define a precise position.
Different purposes of sensors
Source: IoT Sensors and Actuators; Postscapes
Challenges regarding the application of IoT sensors
Sensor accuracy / calibration: Sensors transmit important data. IoT applications rely on accurate data to provide their services properly. Particularly sensors in moving objects or installed outdoors are exposed to deterioration and damage. Sensors integrated in medical devices monitor and steer partially vital functions. Therefore sensors should be easily supervised, checked and replaced.
Battery lifetime: Normally, the job of a sensor consists in starting, powering up, measuring and sending. If an actuator is participating, the tasks receiving, processing and acting before powering down are added to the list. In order to extent battery lifetime, sensors should only be activated for the stated tasks without any „always-on“ periods.
Retrofit options: In terms of reach, it is not sensible to only equip new products with IoT sensors and applications. Companies can gain relevant user groups much faster by offering an IoT retrofit solutions for older product models. That means finding a way to integrate sensors in products that are already in the market.
A sensor is a relatively simple technological item. Nevertheless, the whole IoT value chain of a connected product or product system depends on it. Without the data points, no data analysis and consequently no IoT service. The reliability and the lifetime of a sensor are crucial characteristics for improving the quality of service on the one hand and the adoption rate among customers on the other hand. Especially in B2B areas and safety-relevant products, these basic conditions are really important.
An interesting future competition to IoT products with sensors will come from mobilephones. They are already equipped with a variety of sensors. Proxy measurements are becoming more and more common as substitution of the elaborate integration of the sensors into the core pieces of products. For many applications it is absolutely sufficient to have a good estimate for a data set. IoT product developers should always evaluate this option, too.