SAN JOSE, Calif. — More than 5,000 people registered for this year’s Sensor Expo, where more than 250 companies showed their wares. The numbers are a reasonable indicator that there’s a diverse and growing set of sensors and people interested in them in these early days of the Internet of Things.

I took just two hours out of a busy week to walk the show floor and came away with insights on a handful of the latest products from a mix of big chip vendors and startups.

Along the way, I met Albert Pisano, dean of the Jacobs School of Engineering at the University of California at San Diego. Pisano used to lead a sensor and actuator lab at Berkeley and, in his new role, nourishes a similar initiative focused on wearables.

“We’re not working on things like the Fitbit, a box you strap to yourself,” he said. “We’re interested in bio-compatible devices that work by chemical reactions directly on your skin.”

Pisano described three key use cases that researchers are pursuing: small, long-lasting combination sensors for premature babies, continuous bio-sensors for the aged, and sensors that pharma companies would place on people in their clinical trials.

Among the tech challenges, they must get accuracy up and cost, size, and power down. One interesting technique in the labs uses lactate in human sweat as a power source, potentially strong enough to drive an ultra-low-power radio. It’s still early days for the technique, which, among other things, faces a big-data challenge in figuring out how to calibrate it for the wide differences in individual chemistry.

Size and cost are also major factors in another sensor market said to be one of the hottest sectors in IoT — asset tracking. Modules have dropped from $25 to $15 on average thanks to chip integration and lower-power networks such as LTE CatM and LoRa. The bad news is that carriers have yet to widely deploy stable CatM networks, and LoRa is a do-it-yourself approach still working on roaming, said one engineer showing modules on the show floor.

In other trends, it was clear that attendees aren’t the only buyers at the event. Major exhibitors such as ADI, Rohm, and TDK have been filling out their product portfolios, acquiring smaller sensor vendors over the past few years.

Crowds still gathered on the afternoon of the event's last day. Images: EE Times
Crowds still gathered on the afternoon of the event’s last day. Images: EE Times


Dual radars bolster location accuracy

ADI Dual Radars

Analog Devices featured the 57- to 64-GHz radar sensors that it acquired in February with Symeo. Prior to the acquisition, the Munich-based company had been selling $3,000 systems the size of a baseball aimed at precisely position construction cranes among other uses.

The company’s secret sauce is baked in software running on its own board design using off-the-shelf chips. It enables two of the sensors to collaborate to deliver 5-mm location accuracy over 500 m, an order of magnitude better than a single radar working alone.

ADI has yet to say exactly how and when it will sell the Symeo technology, but from its prominent position in its booth, it’s clear that the company has high hopes for it.


Listening to plumbing over ultrasound

STM Ultrasound MEMS Microphone

STMicroelectronics showed a MEMS microphone capable of picking up 20-Hz to 80-KHz signals, listening deep into the ultrasound spectrum to detect faults such as leaking pipes in a building. Like many sensors at the event, it is a sub-$1 device designed to stream data to a microcontroller running embedded analytics.


Sensor sniffs out product scents

Aroma Bit gas sensor

Startup Aroma Bit sees itself as a data company delivering an odor-analysis service. Its work is based on a proprietary gas sensor that can use 35 thin-film membranes to detect smell. It uses a technique called quartz crystal microbalance that measures the change in frequency of a quartz crystal resonator to determine mass change per area.

The Aroma Coder 35Q box in the background of the picture above acts as a chamber to isolate smells. The startup has catalogued digital signatures of more than 1,000 scents to date. As an example of its use, it showed it providing digital descriptions of the differences in the smell of Pepsi versus Coca-Cola.


Magnetic sensor has all the angles

TDK tunneling magneto resistance sensor

TDK showed its latest tunneling magneto resistance (TMR) sensor. The 360-degree angle sensor provides position to within 0.2 degrees and will sample this fall for the cost of less than $1.

The new TAD2140 is used for products such as car power steering and windshield-wiper motors and in the last year has gotten design wins in smartphones for camera stabilization. It fits in a TO-6 package integrating six capacitors and one resistor to eliminate the need for a board in some uses and supports digital interfaces using an embedded DSP from ICsense, an ASIC design company that TDK acquired in March 2017.


Sensor on plastic helps amputees

PST Sensors flexible plastic substrate sensor

PST Sensors of the U.K. showed its work integrating sensors on flexible plastic substrates. The design above is geared for use inside a prosthesis to monitor and report over Bluetooth temperature, humidity and activity — factors that could affect further deterioration due to diabetes in an amputated limb.

The sensor is going into trials with Britain’s National Health Service this fall. The company is developing a second generation for next year that will be woven into a sock.


Alps reaches for the cloud

Alps sensor variety

Alps of Japan showed its portfolio of sensors (above), one indicator of the diversity of applications in the field. The company showed no new chips at the event. Instead, it showcased its ability to provide an end-to-end IoT solution using its modules, partnerships with gateway vendor, and Mode, a U.S.-based cloud software provider.


Thales seeks middle ground in IMUs

Thales six-axis inertial measurement unit NavChip2

The U.S. arm of France’s Thales is trying to carve out a novel middle market for its six-axis inertial measurement units with its latest NavChip2. The module uses off-the-shelf chips to deliver position with drift of less than five degrees per hour at up to 16G and 2,000 degrees/second. It aims to deliver the capabilities of $1,300 subsystems for cars, drones, and robots at prices ranging from $450 to $300 depending on volumes.


Measuring power at low power

ROHM current sensor

Rohm demoed a tiny contactless current sensor to measure power flow through a printed circuit board using magnetic impedance. The sub-$1 component now sampling slashes power consumption and heat compared to existing approaches based on resistance.


Microchip upgrades touch, security

Microchip capacitive touch sensor

Microchip showed an enhanced capacitive touch sensor embedded into its new SAM L10 and L11 32-bit microcontrollers. The company claims that the chips are the first Arm Cortex-M23 MCUs to support Arm’s TrustZone hardware-based security techniques. The touch sensor inside the MCUs can now capture four signals in parallel and are more immune to noise and moisture than the company’s existing embedded sensors.

— Rick Merritt, Silicon Valley Bureau Chief, EE Times