Flexible Devices Drive New IoT Apps

Printed and flexible electronics are becoming almost synonymous with many emerging applications in the IoT, and as the technologies progress so do the markets that rely on those technologies.

Flexible sensors factor into a number of IoT use cases such as agriculture, health care, and structural health monitoring. Other types of flexible devices are essential to the IoT, especially in wearable gadgets, such as fitness bands and smartwatches.

BeBop Sensors of Berkeley, Calif., is a case in point. The company supplies smart fabrics to develop flexible pressure sensors for OEMs. BeBop’s sensors go into bicycle helmets, car seats, data gloves, shoes, Spandex clothing, and steering wheels, among other products. The smart fabric sensors were originally developed for musical instruments by BeBop founder Keith McMillen for his older company, Keith McMillen Instruments, tying instruments to computers and software.

Fig. 1: Modular data glove. Source: BeBop Sensors

IDTechEx forecasts the world market for printed, flexible, and organic electronics will increase from $29.28 billion this year to $73.43 billion in 2027. Most of that revenue comes from organic light-emitting diodes (OLEDs) going into displays, lighting, and televisions, along with conductive inks. Emerging applications are stretchable electronics, logic and memory devices, and thin-film sensors, according to the market research firm.

Fig. 2: 10-year forecast for flexible electronics. Source: IDTechEx.

Stretchable electronics alone will develop into a $600 million market in the next decade, IDTechEx Research predicts. And MarketsandMarkets has forecast that the components market for flexible electronics will be worth $13.23 billion by 2020.

Anwar Mohammed, a senior director in Flex’s Advanced Engineering Group, was among the keynote speakers at the recent 2017FLEX conference in Monterey, Calif. He spoke about flexible hybrid electronics (mixing printed and CMOS-based components), printed conductors, and stretchable circuits made with roll-to-roll printing, among other topics. “So many wonderful things are being created today, like printed memory, printed transistors, printed pressure sensors, printed sweat sensors,” he said.

Conductive yarn could go into embroidering clothing and outerwear, he noted. Flexible electronics also could incorporate antibacterial technology, he added. This technology can be both hydrophobic and oleophobic.

Mohammed called for the development of industry standards in flexible electronics. “It’s basically a nascent area,” he said. He would like to see the development of printable batteries that could be printed onto fabric for smart clothing, such as jackets.

Jason Marsh, director of technology at NextFlex, said his consortium is working to “de-risk innovation” in FHE, bringing together academia, companies, governments, and not-for-profit institutions. NextFlex has some 25 projects under way, backed with $40 million in funding. The consortium coordinates with IPC, the trade association that develops and maintains standards for electronic assemblies and packaging.

NextFlex is working with SEMI and the Nano-Bio Manufacturing Consortium on flexible and printed battery research and development, according to Marsh. On another front, the consortium is collaborating with Advanced Functional Fabrics of America and the University of Massachusetts at Lowell on a fabric study center.

David Wiens, a product marketing manager at Mentor, a Siemens Business, discussed how his electronic design automation company is addressing FHE design. Mentor has leveraged its printed circuit board design tools for designing flexible hybrid electronics. Its approach is to “optimize design flow from concept to manufacturing,” he said, representing a “3D design and modeling paradigm.”

Flexible hybrid electronics are like printed circuit boards and IC packaging, Wiens noted. Lessons learned in the 1980s from hybrid chips and multichip modules are relevant today for FHE. Electronic design automation can enable early adoption of FHE technology, he added.

Mentor can help “optimize IC I/O for FHE via RDL (redistribution layer process technology)”, Wiens said.

Better health
E-health, telemedicine, and wireless sensor networks are another growth opportunity for flexible sensors.

“Two billion people cannot access a health-care system,” said David Bordonada, a key account manager at Libelium, with responsibilities in the IoT, “cooking hacks,” and channel sales. He previously promoted use of Libelium’s Waspmote sensor platform by educational institutions.

Telemedicine, conducting medical diagnoses and other interactions with patients over the Internet, promises to help people with home monitoring and self-monitoring of medical conditions without having to travel to a doctor’s office, a clinic, or a hospital. Employing telemedicine technology could save billions of dollars on public health services, according to the Commonwealth Scientific and Industrial Research Organisation in Australia.

By employing wireless sensor networks and cloud-based computing services, significant cost reductions can be realized in health care, Bordonada said. Low-cost sensors can be used for early detection of childhood diseases, he noted. Libelium has been active in helping to reduce childbirth deaths of mothers in the Dominican Republic.

Better tomatoes
Francis Gouillart, president of the Experience Co-Creation Partnership, described the work with Analog Devices and ripe.io in the Internet of Tomatoes project, which uses flexible hybrid sensors to track tomatoes through the processes of planting seeds, tending to the plants, monitoring the ripeness of the fruits, and transporting the harvested tomatoes through the food supply chain. Ripe.io provides blockchain technology for agriculture and food.

Fig. 3: The Internet of Tomatoes. Source: Analog Devices

Environmental sensors are used at the tomato farm, along with temperature and humidity sensors, according to Gouillart. Once tomatoes are picked, optical non-destructive sensors can keep an eye on their conditions.

“Forty percent of tomatoes are wasted in growing, transportation, and handling,” he said.

Under the federal Food Safety Modernization Act, buyers can speed up their regulatory reporting to the government. “Blockchain can play a role,” Gouillart said. Small farms can benefit from precision agriculture. “Locavores” can keep tabs on how many miles tomatoes are transported, bolstering the “eat local” culinary movement. There are also considerations in modeling ripeness and predicting taste through sensor technology. “De-commoditizing food is the ultimate goal,” he asserted.

Gouillart outlined 10 issues confronting the agriculture and food industry, discussing how sensor technology can resolve some of those issues.

He also serves as CEO of Stock Pot Malden, a shared-kitchen incubator for food trucks and food-product entrepreneurs working on a healthy, sustainable agriculture/food chain in the metropolitan Boston area.

Better everything
OE-A, an international association for printed and large-area flexible electronics—a working group within the Verband Deutscher Maschinen- und Anlagenbau (VDMA)—just released the seventh edition of its Roadmap for Organic and Printed Electronics in March. Stan Farnsworth, chief marketing officer of NovaCentrix and a member of OE-A, noted that Audi’s 2017 TT incorporates an OLED production bumper assembly. It is the first vehicle to use that technology, Farnsworth noted.

Curved OLED displays are becoming common in smartphones, smartwatches, and televisions, he said. “Printed batteries and supercapacitors are emerging,” he added. Unlike the U.S., the European Union places no battery restrictions on the use of supercapacitors. “Integrated smart systems” are being developed for the IoT, wearables, health, and well-being applications, he said.

Technology has enabled the development of fully printed radio-frequency identification and near-field communication labels, Farnsworth said. OLEDs, long touted for their longer lifetimes, are also improving in luminosity. He added that the “key parameters” for organic and printed electronics, going forward, are standards, cost, capital expenditures, and reliability.

Brewer Science of Rolla, Missouri, is involved in advanced lithography, wafer-level packaging materials, and printed electronics. It offers the InFlect line of sensors, which use conductive carbon junctions for detecting external stimuli. Brewer has a flexible (bending) sensor, along with devices for sensing moisture and temperature.

“The Internet of Things is extremely broad in terms of its scope,” said Dominic Miranda, Brewer’s business development manager for printed electronics. Printed and flexible electronics are flexible, literally and figuratively, for IoT applications, he added. Wearables represent a “new wave of IoT,” requiring flexible substrates, he said.

Fig. 4: Flexible sensor. Source: Brewer Science.

These printed and flexible sensors can be deployed in large arrays at reasonable costs, made with roll-to-roll manufacturing equipment, according to Miranda.

“We move up into the area where you start talking about the Internet of People, really,” Miranda said. “You can have these types of sensors, or any type of printed sensors like this, in clothing, or personal devices, wearable devices, which would pretty much mean ubiquitous sensing capabilities and potentially trillions of devices in the market that have various capabilities.”

Moisture sensors can be used in precision agriculture, where soil moisture is more critical for growing grapes than for growing corn, according to Miranda. Large sensor arrays for the IoT can present “a really powerful tool” for wineries, he said.

Roll-to-roll processing of IoT sensors is an advantage, not a critical factor, in lowering sensor costs, Miranda said.

Brewer’s printed sensors are “relatively simple, at least in terms of their construction,” Miranda said. “These aren’t highly complex sensors. They are technologically advanced, but they aren’t highly complex. When you start looking at some of the things that we’re working on in the future, there’s a lot more complexity in terms of the printing and things we’re doing in the system architecture of the arrays, or the sensors. We’re getting into more and more complex and diversified sensor capabilities that we hope to see in the very near future, in a year or so.”

Brewer Science is looking forward to the development of pH sensors, water analyte sensors, and hydrogen gas sensors, among other products.

The IoT and PFE have a long road of research and development ahead for these technologies.

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