Sensors, Actuators and IoT
When I attended a recent internet-of-things (IoT) conference, I kept hearing the same question: So What? The IoT industry continues to build devices, but how many IoT devices do something that’s truly useful and for whom? This blog post is the first in a series working to answer that question. Here I offer a framework dividing IoT into sensors and actuators.
Applying the language of MEMS to IoT
Micro-electro-mechanical systems (MEMS) are computer chips with moving parts that are typically divided into sensors and actuators. For example, the screen on your smartphone ‘knows which way is up’ because there’s a sensor inside with vibrating parts used to detect gravity. As Steve Jobs said, “Good artists copy, great artists steal,” so I propose stealing the MEMS sensors-and-actuators and applying it to IoT devices, not unlike Jobs stealing that quote from Picasso.
What’s important about MEMS, and what’s most applicable to IoT, is that both are transducers: devices that change energy from one form into another form. An everyday example of a transducer is a musical instrument, like a guitar or a drum kit, that transforms mechanical energy into acoustic energy. Watching Tito Puente’s hands move is nice, but hearing his latin rhythms is something special. Puente could easily control and manipulate his hands, but So What? Well, the timbal drums enabled him to transform the motion of his hands into the music that we enjoy. That’s the key to MEMS, IoT, and transducers in general: going between energy in the form of electrical data signals that we can easily manipulate and energy we enjoy in the form of the light we see, the music we hear, or the vibrating pulses we feel.
Within transducers and MEMS, there’s a distinction between sensors and actuators. A sensor transforms interesting, useful energy into electrical data. By contrast, an actuator transforms electrical data into interesting, useful energy. Our smartphones are full of transducers — the camera and microphone are sensors whereas the speakers and screen are actuators.
The most popular examples of IoT devices are wearable activity trackers, you can think of Jawbone and Fitbit, as well as smart home devices, like Hue and Nest. Jawbone and Fitbit are sensors that generate data about steps; the Hue is an actuator that emits light; and, Nest has both, it senses temperature and motion, and also actuates (turns on and off) the furnace.
IoT needs more actuators
Applying the framework of sensors and actuators to IoT illuminates the IoT market. First, we recognize that although IoT sensors provide useful data, it’s only IoT actuators that provide the So What that the market is seeking. And second, we see a major challenge in IoT today: there are many more sensors than actuators. As we work to make IoT more relevant — to provide compelling answers the So What? question — we need more devices like Nest and Hue that actuate. A few of my favorite IoT actuators are Lully, a device that both senses sleep quality and vibrates to enhance sleep, and Sentri, a smart home security system that alerts users to air quality and security threats. Let us know your favorite IoT actuators by tweeting us at @TheNeura or on Medium @Neura.
