By Luca Fontanella and Simone Ferri

Over the last three years the number of battery-operated electronic-component solutions for the Internet of Things (IoT) and Industrial IoT (IIoT) applications has been increasing steadily. This trend will continue for years to come, particularly with the growing popularity of mobile devices of all flavors. Addressing power consumption for battery-powered always-on IoT/IIoT devices – which rely on dozens of electronic components, including sensors — is critical to their commercial success.

The demand for ultra-low-power sensors has accelerated the race to squeeze every last mW from components. Compared to previous-generations of sensors, semiconductor suppliers have managed to drastically reduce power by as much as 50%-60% over older solutions. Leveraging new state-of-the-art analog design techniques, we have effectively optimized capacitive readings of MEMS structures. How effective are they? We estimate that with the right mix of our company’s power-saving technologies, it is possible our customers could save 3MW/year globally[1].

What’s next?

While the semiconductor industry continues to investigate novel technologies, approaches and analog IP for greater energy efficiency, we believe that bigger gains in reducing power consumption will come from thinking at the system level. The sensor node is a good place to start.

A typical IoT node is composed of a set of sensors, a microcontroller, a radio frequency (RF) link, and a power-supply system, often based on Li-Po batteries.

Of these, the microcontroller and RF link consume the most energy and, in the RF link, power consumption is a function of the distance between end point and receiver and of the amount of data transmitted. Thus, at longer distances reducing the amount of data transmitted can save power. We can achieve this by including some pre-elaboration capabilities on-board and by extracting more meaningful information from the raw sensor data.

We address this by moving some computation and data analysis inside the sensors, where smart hardware “digital blocks” perform faster and more efficiently than software-based routines running in the microcontroller. We can achieve this by using dedicated hardware resources to reduce overall system power consumption. The beauty of this solution is that it allows the microcontroller to operate in low-power states by only transmitting significant information in batches. The SensorTile development kit can speed up prototyping of ultra-low-power IoT devices by integrating an ultra-low-power MCU and BlueNRG Bluetooth radio with sensors. Some examples of these advanced digital blocks are the Advanced Embedded Pedometer, the Finite State Machine and Decision Tree, and Compressed FIFO in an IMU.

The Advanced Embedded Pedometer is a hard-wired step counter that works independently inside the sensor, without CPU intervention: By comparing sensor outputs to pre-defined and -loaded patterns, it autonomously decides whether the user is walking or running to start and stop counting the user’s steps. The sensor then makes this information available to the microprocessor for further elaboration or for simple notification to the user.

The Finite State Machine and Decision Tree are new functions dedicated to pattern recognition (machine learning) and decision-making: They can perform complex classifications and state detection, and can send dedicated warning and signaling to the microprocessor. A good real-world example is industrial predictive maintenance, where the sensor can categorize and identify different malfunctioning states in the equipment before waking the microprocessor to react.

Our products, on average, save about 1 mA (1e-3) over competitive devices or over our previous-generation parts. So 2.0 x 1e-3 x 1.5e9 = 3MW.

Another example is compressed FIFO (first-in, first-out) buffer, which can store sensor data in the sensor, not in raw format, by using efficient compression algorithms. In addition to saving memory (and therefore silicon area) inside the sensor chip, it also saves power by reducing the number of bytes transferred to the processor and by shortening the communication data flow, which reduces processor-active time.

These examples – the Advanced Embedded Pedometer, the Finite State Machine and Decision Tree, and compressed FIFO buffer – are just some showing that we can develop low-power IoT/IIoT devices through intelligent management of sensors, microcontrollers and other components in any given system. Your starting point is an IoT/IIoT node that lets you selectively allocate some power-hungry tasks — such as computation and data analysis — to sensors instead of the microcontroller. Leveraging data blocks that reside in the sensors alleviates the microcontroller’s typical power drain, allowing the microcontroller to operate with maximum efficiency.

[1] ST sells about 1.5 billion pieces/year (1.5e9), which typically run from a 2V supply.

Luca Fontanella joined ST Microsystems in 1995 as an analog designer. In 2001 he joined the MEMS team in a marketing role and today he is marketing manager in the MEMS Sensor Division. Luca has contributed to 25+ international patents and has presented at multiple conferences. He earned a degree in Electronic Engineering from Padua University.

 

Simone Ferri joined STMicroelectronics in 1999 as Central R&D engineer, moved to the Audio Division as a digital designer and is now director of the Consumer MEMS Business Unit. He holds a degree in Electronic Engineering and an MBA from the Polytechnic of Milan.

By Dr. Alissa M. Fitzgerald, founder and managing member, A.M. Fitzgerald & Associates, LLC

When developing industry forecasts, market analysts gather data from hundreds of companies to provide actionable insights on established technologies and to identify near-term business opportunities. As a developer of new MEMS and sensor technologies for a range of commercial applications, clients often ask us, “What’s going to be hot?” Gauging the promise of emerging technologies that are five to 10 years from commercialization requires taking a different tack.

History tells us that most of today’s blockbuster MEMS products were born as academic research projects. Years of hard work by entrepreneurs, funded by millions of dollars, have turned proof-of-concept research into new commercial products. To identify up-and-coming technologies, we gather information straight from the source: academic conferences and articles.

Chirp Microsystems is a good proof point of our research methodology: In my 2012 report on emerging technologies, I highlighted research from UC Berkeley and UC Davis on “In-Air Ultrasonic Rangefinding and Angle Estimation Using an Array of AlN Micromachined Transducers.” Soon after publication, the authors incorporated Chirp Microsystems to commercialize their technology for gesture- and fingerprint-recognition applications.

After five years of development work, Chirp’s products are entering the marketplace. In February 2018, the global supplier TDK InvenSense acquired Chirp, underscoring the company’s commercial potential. At October’s SEMI-MSIG MEMS & Sensors Executive Congress in Napa, Calif., Chirp’s CEO, Dr. Michelle Kiang, held attendees rapt as she described her company’s journey from startup to wholly owned subsidiary.

There’s a method

This year, I reviewed over 100 papers from top researchers presenting noteworthy technologies at the Hilton Head Workshop on Solid-State Sensors, Actuators and Microsystems. My criteria for selection were: commercial relevance; offers a solution to a known or anticipated problem; and technology game-changers. The following caught my eye:

• Event-driven sensors: Cleverly designed silicon MEMS that consume no power while standing by. A triggering mechanical or thermal event closes a contact within the sensor to activate its circuitry and telemetry. These sensors leverage existing fabrication methods, so they could become commercial products within five years for event monitoring and security applications. (UT Dallas, Northeastern University)
• Thin film piezoelectric resonators: Advances in PZT deposition methods and process integration with CMOS were used to create monolithic acoustic waveguides for RF filtering in 5G applications. This new filter design, using existing scalable processes, is ripe for commercialization. (Purdue University, Texas Instruments)

• Intra-body communications: MEMS ultrasound transceivers, made from aluminum nitride, can send data directly through flesh at Mbit/s data rate. With trends toward networks of multiple implanted or wearable medical devices, this innovation would enable medically safe, secure, intra-body wireless communication. This early-stage work still needs in vivo validation and would likely require 10 or more years for development and regulatory approval. (Northeastern University)
• Screen- and 3D-printed sensors: One example of many exciting innovations using screen- and 3D-printing are potentiometric nitrate soil sensors. Low-cost and biodegradable, these sensors could be spread over huge areas to monitor a farm’s soil quality. Table-top and hobbyist tools are currently used to make screen- and 3D-printed devices, so new manufacturing equipment and infrastructure must be developed before commercial production could occur. (Purdue University)
• Biodegradable batteries: A paper-based battery that can deliver 0.5 uW of power, ingeniously using bacterial metabolism as the electrolyte. These batteries dissolve in water and could one day be used to power temporary medical implants or biodegradable sensors. This exciting proof-of-concept prototype will require significant process development and new manufacturing infrastructure

To read more about these technologies, please download my presentationfrom SEMI-MSIG’s MEMS & Sensors TechXpotat SEMICON West 2018.

Alissa M. Fitzgerald, Ph.D., is the founder and managing member of A.M. Fitzgerald & Associates, LLC, a MEMS and sensors development company in Burlingame, CA. She has over 20 years of engineering experience in MEMS design, fabrication and product development and now advises clients on the entire cycle of product development, from business and IP strategy to manufacturing operations. She is a frequent speaker at industry conferences and currently serves as a director of the Transducer Research Foundation, sponsor of the Hilton Head Workshop.She received her bachelor’s and master’s degrees from MIT and her doctorate from Stanford University in Aeronautics and Astronautics.

For more information, visit: www.amfitzgerald.com

By Maria Vetrano

SEMI-MEMS & Sensors Industry Group (MSIG) welcomed a global group of industry executives to its 14^th annual MEMS & Sensors Executive Congress (MSEC), October 29-30, 2018 in Napa, Calif. MEMS and sensors represent a robust sector of the electronic industry. Analyst firm Yole Développement expects the global market for MEMS and sensors to double in the next five years, reaching $100B by 2023, spurred by growth of autonomous mobility products such as Internet of Things (IoT) devices, autonomous cars, fitness and healthcare wearables, and agricultural sensors.

“From drones that navigate any terrain in all lighting conditions, robo-taxis that ‘smell’ cigarette smoke, and sensors that monitor animal welfare and food safety, MSEC speakers shared inventive use cases representing new opportunities for MEMS and sensors suppliers,” said Carmelo Sansone, director, MEMS & Sensors Industry Group. “Our keynote speakers spurred attendees to collaborate for the greater good. MITRE Corp. cybersecurity expert Cynthia Wright exhorted attendees to proactively address cybersecurity. DARPA Microsystems Technology Office (MTO) program manager Ron Polcawich invited participation in a rapid innovation and production concept that could dramatically speed design cycles for new MEMS. They exemplify the cross-pollination among commercial industry, government and academia that will continue to advance MEMS and sensors.”

Getting serious about cybersecurity

MITRE cybersecurity expert Cynthia Wright opened MSEC 2018 with a keynote on cybersecurity, alerting attendees to a topic that few in the industry have explored in-depth — but to which they need to pay attention.

“Billions of connected mobile devices democratize knowledge, diversity and boost economies, and accelerate innovation by connecting humans to one another and to our environments,” said Wright. “At the same time, they easily create huge networks that carry operationally and personally sensitive data.”

Because MEMS and sensors are deeply embedded into this vast array of connected devices, industry needs to get involved now or risk potentially grave consequences, claimed Wright. “From the destruction of critical infrastructure, cyberattacks on life-critical medical devices such as insulin pumps and heart monitors, and intrusions on autonomous vehicle safety systems, MEMS and sensors suppliers have a responsibility to help improve cybersecurity of connected devices,” she added.

Allaying the potential fears of a roomful of suppliers envisioning complete redesigns of their products, Wright said that not every device requires the same level of security, and suppliers can make a difference with even “minor tweaks.”

Wright suggested encryption at the edge and process authentication. She also gave MSEC attendees a list of design precepts:

• Build it in. Don’t bolt it on — Design your device with security in mind instead of retrofitting it after-the-fact to realize the most elegant design.
• Beware of shadow IT — You can’t protect what you don’t know about. Consider physical asset security; software/sensor-guided decision-making; personal or operational data collection; and key process control.
• Realize your points of vulnerability — because MEMS and sensors are susceptible to spoofing.
• Learn from cyberattacks of the past — even if they have not been tied directly to MEMS/sensors.
• Understand IoT software — Realizing that IoT software acts on what the hardware tells it, pay attention to altered sensor data that can lead to altered system performance.

When asked about the role of US government regulation on the security of connected devices, Wright acknowledged that Europe has more restrictive cybersecurity guidelines than the US.

“At the same time, it does not make sense to have two different approaches to cybersecurity of devices. US suppliers who implement more security measures can sell to both markets and to other parts of the world.”

If she could leave MSEC attendees with a closing thought, it might be that companies “don’t need to put a firewall on a toaster.”

“Not every chip has to be secure-foundry secure, but it would be nice if even 10% could hit that mark,” added Wright.

Rapid Innovation through Collaboration

IC designers typically enjoy three to four design cycles in a calendar year, leading to swift advancement of electronics over subsequent years.

Designers in the MEMS community, however, generally have access to one design cycle or less per year, and typical time-to-market is four years for a new product. That slow fabrication pace has hindered deployment of innovative MEMS designs — and it’s something that MSEC closing keynote speaker, Ron Polcawich, program manager, DARPA MTO, would like to change.

Polcawich’s vision of government collaboration with industry and academia spawned the investigational Rapid Innovation through Production MEMS (RIPM) Workshop, which Polcawich and his team held in May 2018. During his keynote, Polcawich shared lessons learned from the workshop while inviting MSEC attendees to get involved.

Before RIPM can become a program, Polcawich knows it will require definition. What would a program concept look like? What is the best way to articulate the potential benefits to the MEMS community, and what additional inputs would be needed?

“This is a daunting challenge from a program planning perspective,” said Polcawich. “In developing RIPM, we realized that we needed representatives from the entire MEMS ecosystem – integrated device manufacturers, or IDMs, equipment suppliers, foundries, and materials’ providers — to literally come to the table to tackle a common goal. Given the potential for the MEMS industry at large to benefit from rapid innovation and production, we hoped that competitors would realize that leveraging established MEMS processes could deliver significant benefits over the historically entrenched approach: one product, one process.”

Polcawich believes that MEMS suppliers might relinquish the one product, one process paradigm if they knew that their IP were secure.

“While technical challenges to realizing RIPM abound, we knew that we could tap the MEMS industry’s vast knowledge base to address them,” he said. “IP protection is an equally complex issue, and one that may bear a range of approaches. One model could ensure that each IDM owns their IP while the foundry owns the process technology, which it licenses to other companies through process development kits. In addition to speeding innovation, it also provides new revenue sources for the industry.”

Polcawich sees RIPM as a win-win for both commercial industry and for the DoD. Speeding design-to-deployment of new MEMS devices could open new and larger markets to MEMS suppliers. It could also support greater product-line diversification and new revenue streams for foundries and other ecosystem members. The DoD could tap new MEMS devices for strategically important applications like tactical radios, unmanned aircraft systems such as drones, and image autofocus for cameras. Polcawich encouraged SEMI-MSIG members to get involved by emailing his group: [email protected]

New Hall of Fame Members

Three new industry leaders joined the SEMI-MSIG Hall of Fame, first established in 2011 as a means of honoring those who have made a substantial contribution to SEMI-MSIG. Selected by members of the Governing Council, 2018 Hall of Fame inductees include:

• Michelle Bourke, strategic marketing director, Customer Support Business Group, Lam Research
• Eric Pabo, business development manager, MEMS, EV Group
• Yoshio Sekiguchi, senior strategic advisor, TDK InvenSense

Technology Showcase Winner

MSEC recognizes the latest advancements in applications enabled by MEMS and sensors — including those demonstrated by entrepreneurs competing in the Technology Showcase. Selected by a committee of industry experts, five finalists did their best to impress attendees with their technical approach and go-to-market strategies.

The 2018 Technology Showcase winner, Alertgy, presented a biosensor-based wristband device that provides non-invasive, real-time blood glucose monitoring for people with type 2 diabetes, which affects more than 20 million Americans and hundreds of millions more worldwide.

MSEC 2019 will take place October 22-24, 2019, at the Coronado Island Marriott Resort & Spa in Coronado, Calif., just minutes from downtown San Diego.

For more information on MSEC 2019 and other SEMI-MSIG events and programs, please follow @MEMSgroup on Twitter, visit MSIG at SEMI and subscribe to SEMI’s weekly newsletter, SEMI Global Update.

Maria Vetrano is a public relations consultant at SEMI.