Wearables and MEMS – the perfect storm ?

The "wearables" market comprises hearables (wearables for your ears), smart watches, wristbands, and more. These electronic devices are used for a wide range of applications, from health tracking and data logging to mobile payments. According to a new International Data Corporation (IDC) report, global shipments of wearables could reach 396 million units this year. IDC also claim that The global wearables market grew 35.1% year over year during the third quarter of 2020 (3Q20) with total shipments reaching 125 million units 

As for the future, “IDC forecasts shipment volume to have a five-year compound annual growth rate (CAGR) of 12.4% and total 637.1 million units in 2024.” This year, hearables lead the way with a 59% market share, followed by watches (23%), wrist bands (17%), and other wearable devices.

Interesting information in its self but what’s driving that growth ? Lets see what what the experts are saying.

"Wearable devices and services will evolve together in the coming quarters," said Ramon T. Llamas, research director, Mobile Devices and AR/VR. "Wearables are the perfect device to collect user data and services provide guidance and actionable insight. Together, they offer the user a virtual coach to make better decisions and achieve their goals." 

"Device makers are also laying the groundwork that will allow consumers to use multiple wearables in conjunction with each other," said Jitesh Ubrani, research manager for IDC Mobile Device Trackers. "Imagine tying positional and audio input from hearables with health metrics from the wrist to gauge a user's level of attention or excitement in the surrounding environment. That's a powerful new experience that can bring added utility to consumers and vendors alike."

So effectively the growth of wearables in the future is expected to be based on wearables being able to collect data and provide actionable insight from multiple sensors from different vendors. But how easy is that going to be achieved  and whys it not happened already ?

Well up to now capturing data from the individual  and their environment has involved a plethora of sensors from multiple vendors. All of these sensors providing information at different times, and over different communications media, and of course at great cost. Based on this its difficult to see how you will achieve the volume of sensors on an individual or an area to provide the information that enables this guidance and actionable insight to be achieved. Fortunately the world of sensors is changing forever  with the advent of MEMS or microelectromechanical systems.

MEMS refers to technology that allows mechanical structures to be miniaturized and thoroughly integrated with electrical circuitry, resulting in a single physical device that is actually more like a system, where “system” indicates that mechanical components and electrical components are working together to implement the desired functionality. Thus, it’s a micro (i.e., very small) electrical and mechanical system.

People tend to look down on mechanical components as being less advanced than electronics based solutions. This does not however mean that the mechanical approach is always inferior. The mechanical relay, for example, is far older than transistor-based devices that provide similar functionality, but mechanical relays are still widely used.

Nevertheless, typical mechanical devices will always have the disadvantage of being much larger in comparison to the electronic components found in integrated circuits. The space constraints of a given application may cause electrical components to be favored or required, even when a mechanical implementation would have resulted in a simpler or higher-performance design.

MEMS technology represents a conceptually straightforward solution to this dilemma: if we modify the mechanical devices such that they are not only very small but also fully compatible with integrated-circuit manufacturing processes, we can, to a certain extent, have the “best of both worlds.” However, whist MEMS is conceptually a straightforward solution. As you might expect, coming up with the idea of a microscopic mechanical device is much easier than actually building it.

This is a physical gear and chain. This machinery moves and functions as you would expect a gear and chain to move and function. However, the links in the chain are about 50 μm long—i.e., less than the diameter of a human hair. Image courtesy of Sandia National Laboratories.

The tiny mechanical structures in a MEMS device are fabricated by physically modifying silicon (or another substrate material) using specialized. These silicon mechanical structures are then combined with silicon integrated circuits, and the resulting electromechanical system is enclosed in packaging and sold as a single device.

As explained in a paper on MEMS published by Loughborough University in England, MEMS devices make use of micromachined structures, sensors, and actuators. Sensors allow a MEMS to detect thermal, mechanical, magnetic, electromagnetic, or chemical changes that can be converted by electronic circuitry into usable data, and actuators create physical changes rather than simply measure them.

MEMS technology can be incorporated into a wide variety of electronic components. Whilst time will tell, generally the belief is that MEMS devices are smaller, cheaper and in most cases simpler to interface to than traditional devices due to the fact that the logic required to integrate them is built directly into the device. Effectively this makes them easier to integrate into wearable devices. 

MEMS technology has been incorporated into four product categories:

·      Audio

·      Sensors

·      Switches

·      Oscillators

The first two being particularly important in the world of wearables. 

In the audio domain, we have MEMS microphones and MEMS speakers. But in the MEMS world these become digital devices rather than the traditional analogue devices. In the case of Sensors there are MEMS gyroscopes, inclinometers, accelerometers, flow sensors, gas sensors, pressure sensors, and magnetic-field sensors.

As a result of this companies such as Nevadanano are bringing out multi gas sensors at low cost, increased reliability and simpler use due to the integrated electronics. Researchers and engineers from the Graz University of Technology, ams, and Silicon Austria Labs have developed with world's smallest particle sensor. According to TU Graz, the technology is aimed for use in smart phones, wearables (e.g., smart watches), and various other mobile device. The sensor can “measure the quality of the ambient air in real time” and alert the user to elevated dust levels, TU Graz reports. How small is “small”? The compact particle sensor measures 12 mm × 9 mm × 3 mm.

This pioneering work is commoditising sensors in a way never seen before and allowing them to be embedded into wearable devices at a lower cost that people never thought possible. The question is – is this the perfect storm for wearables and is this going to drive the growth that analysts predict ?