Wearable devices are finally transitioning from hype to mainstream, aided by integration of valuable transducers, identification of application and use cases, ramp up of cloud services, and increased public awareness and interest due to Apple’s watch introduction. Although still a nascent field, several themes are emerging:
- Wearables are evolving from ability to perform simple functions such as step count, to becoming contextually aware products, providing richer user experience and data (health, fitness, infotainment, IoT control). These capabilities are in turn enabled by a plethora of transducers such as accelerometers, gyroscopes, magnetometers, pressure sensors, haptics, and microphones. Many new sensors and actuators are either being integrated or are just on the horizon: Heart Rate Monitor (HRM), Ambient Light Sensor (ALS), Ultraviolet detector (UV), temperature and humidity (RH&T) and gas and chemical sensors.
- The wrist is only one of many targets for these devices. Smart glasses, hearables (ear as a natural place and rich with health information), necklaces, finger and hip worn products, and smart clothes are all becoming realities. Due to severe size constraints, several new user interfaces, such as audio, are becoming critical.
- Due to the desire for “always on” capability, small size limit, and appeal of charging only every few days, power is one of the most important parameters impacting the entire system design: Innovative circuit techniques target extreme low power. Smart combo sensors (MEMS SOC) handle tasks locally on chip instead of sending raw data to processor/cloud. Dedicated algorithms and software running on these smart combo sensors further reduce the system power (e.g. run-time calibration, streaming/batching of data, automatic activity recognition, heavy duty cycling of power-hungry functions such as GNSS). Low-power wireless links enable connectivity of wearables to smart phones and other devices, and eventually to the cloud. Although significant strides have been made in reducing power consumption, another order of magnitude improvement is needed for truly ubiquitous adoption of wearables
Fari Assaderaghi is Vice President of Advanced Technology Development at InvenSense. He is tasked with expanding company’s product portfolio beyond inertial sensors, including MEMS-based audio solutions. He earned his M.S. and Ph.D. degrees in Electrical Engineering from UC Berkeley in 1992 and 1994, respectively. After graduation, Dr. Assaderaghi joined HP Labs. From 1995 to 2001 he was with IBM TJ Watson Research Center where he contributed to the development of first commercial version of CMOS SOI for VLSI. This technology became the workhorse for IBM’s microprocessors and was used in Apple’s processors, as well as Sony Playstation Cell Processor. From 2001 to 2003, he was the technology director for Silicon Wave Inc., developing Bluetooth products. From 2003 to 2008, he was with Rambus, as senior director of engineering. His groups were responsible for developing high speed data communication circuits and systems, including the breakthrough Terabyte/sec signaling initiative. From 2008 to 2012, he was with SiTime, a developer of MEMS-based timing products. As Senior VP of Engineering and Operations, he was responsible for development and manufacturing of all SiTime’s products. During his tenure, he helped grow the company’s shipments from less than 1 million to over 50 million units/year. His areas of interest include mixed-signal and high speed circuit design, semiconductor device physics, process integration, and MEMS. Dr. Assaderaghi has contributed to more than 100 technical papers and holds over 50 patents.