Jonah McLeod, Director Marketing Communications, Kilopass Technology Inc.

Wearable semiconductors are not new. In the early 1970s, Intel, National Semiconductor and others introduced the first wearable semiconductor devices, the digital watch. A novelty back then, the digital watch never became the killer app that everyone imagined. Today, the digital watch has given way to wearable sensors that measure physical activity and share the wearer’s daily output with friends on social networks. There are also medical devices that monitor chronic health conditions of an increasing percentage of the population.

“Individually, these applications represent modest markets on their own, but collectively, do they represent a major new application of semiconductor technology?” declared Mike Noonen, co-founder silicon catalyst and experienced longtime follower of wearable and low power devices at National Semiconductor, NXP and GlobalFoundries “If so what elements within the industry will profit from this growth: analog/mixed signal, the growing MEMS collective; more mature or leading edge process technology.” This article will examine the wearable applications with the greatest potential and suggest the impact they will have on the semiconductor industry.

Since the consumer electronics industry has most recently fixated on reimagining the digital watch, it would be enlightening to view recent efforts in the field and to examine the cause of their failure to achieve mass-market appeal. The poster child of recent efforts is the Microsoft Spot Watch. It hit stores at the end of 2003 and was discontinued last year. It used an FM subcarrier to distribute information such as weather and news tickers and the like, thus adding functionality beyond analog watch replacement. “Microsoft engaged fashion brands to back the new device hoping to give it a sense of “cool.” The problem was great technology and consumer backing from giants like Swatch and Fossil bringing out devices with their brand backing still couldn’t overcome the product’s power problem,” Noonen stated. “It needed to be docked every night to recharge its battery. The irony is that the least fashion conscious industry on the planet was attempting to create a device, the watch, known more for its fashion esthetic than for its essential function.”

Fast forward to today and what has changed? From a technology standpoint the industry is producing handheld solutions—smart phones and tablets—that offer enough battery life that users are willing to spend time charging these electronic gadgets. Second, the sensors and radios in these devices have advanced sufficiently to provide additional, meaningful benefits to the consumer. “Today’s wearable offerings are not just replacing a watch, they’re collecting data and communicating it to the cloud, where further functionality—social connectivity—can be added,” Noonen asserted. “Bluetooth low energy is part of the reason.”

To gauge the impact wearables are likely to have on the semiconductor industry, what total available market exists for these devices? According to research from International Data Corporation (IDC) released this past April, wearables took a huge step forward over the past year and shipment volumes will exceed 19 million units in 2014, more than tripling last year’s sales. From there, the global market will swell to 111.9 million units in 2018, resulting in a CAGR of 78.4 percent. To put these numbers in perspective, the Framingham, Mass. market research firm in January this year reported that the smart phone had shipped 1,004.2 million smartphones worldwide at the end of 2013, up 38.4 percent from the 725.3 million units in 2012. Still, wearables have made a respectable start at catching up.

The one handicap for wearables is that no one application resembling the smart phone has emerged to jumpstart the industry’s growth. The question is what do consumers do with this new technology? The three categories that have emerged that seem to be getting traction are activity monitors, such as FitBit; health monitors—heart rate, blood sugar, etc.; and added functionality digital watches—e-mail, Twitter, Facebook,… post notifications and some activity monitoring functionality. None of these yet have the mass-market appeal that will catapult the market into the smart phone category.

“Some of the new devices that showed up at the Consumer Electronics Show in January included devices that will monitor the environment,” Noonen added. “For example, one company exhibited a piece of jewelry that measured UV exposure the wearer is subjected to, a fashion statement with a real purpose. Another device suggested by the CTO of LG Electronics measures the amount of oxygen in a room. Pollen density measurement is another candidate for wearables. However, the problem that presents itself is now that the wearer knows he/she is in a high pollen area, how does the wearer act on the information? If the user has more information about his/ her environment does this information change his/her behavior? If the answer is that it doesn’t then the obvious question is why have the device?”

There is still a whole world for wearables to exploit regarding how disease and health conditions manifest themselves in the body. “If there were a wearable on the person’s body taking measurements over a longer period of time the result is more meaningful contextual data,” Noonen observed. “Also being able to monitor temperature, blood pressure, heart rate and others metabolic functions at a distance, enables automating the management of chronic illnesses. For example, today, diabetic blood glucose testing involves taking a blood sample and looking for a pH level of some amount.” Google X in January described a contact lens that can monitor diabetics’ blood sugar levels by testing their tears (see Fig. 1). Google is in the early stages of testing the device and in early stage discussion with the Food and Drug Administration. The tiny chip embedded in the contact lens computes the blood sugar level by analyzing the chemical structure of a tear sample every minute then wirelessly transmits the results to a wearer’s mobile phone. With 25.8 million Americans, 8.3 percent of the population, having diabetes, according to the American Diabetes Association, only 18.8 million diagnosed, this application represents a reasonable sized market.

Figure 1. Google X Experimental Contact Lens Glucose Monitor

Figure 1. Google X Experimental Contact Lens Glucose Monitor

Another example of a health-care-providing wearable is the biostamp (see Fig. 2). The invention of John Rogers, Lee J. Flory Chair Founder Professor of Engineering at the University of Illinois, Urbana-Champaign, and founder of MC10 Inc. of Cambridge Mass. who pioneered conformal electronics technology: flexible electronics that can be applied to the skin or attached to an organ like the heart. Operating from harvested energy and communicating its data to a patient’s mobile phone, an application running in the cloud can continuously monitor the health of the individual. The biostamp is expected to cost less than ten dollars per unit, and MC10 aims to have a commercial product in the next five years.

Wearables to address health care is an attractive market because the demand is being driven by the need to contain the growing cost of health care while improving the health of the individual. According to the Partnership to Fight Chronic Disease, in 2005, the U.S. spent $2 trillion on public and private health care, of which 75 percent $1.5 trillion was for treating chronic conditions—roughly $5,000 per person. And health care spending is growing at around 45 percent per year.

Figure 2. MC10 Biostamp: A Stretchable, Twistable, Wearable Chip

Figure 2. MC10 Biostamp: A Stretchable, Twistable, Wearable Chip

A wearable has to be designed with the lowest possible power consumption in mind, the energy harvesting of the biostamp being a perfect example. Low power consumption means long battery life. After power the concept of situational awareness is the other requirement for wearables. The mobile device monitoring the wearable must have an understanding of where the wearable is and what it is reading.

The wearable presents some new challenges for the semiconductor industry as illustrated by the Google contact lens and the MC10 flexible electronic circuit. For example, MC10 leverages the advances made in semiconductor technology driven by Moore’s Law. However, new manufacturing processes are being developed to create bendable, stretchable semiconductor circuits that can conform and adhere to human tissue.

To manufacture these circuits requires techniques that don’t involve the advance processing of today’s logic CMOS circuits but do require new processing steps to reduce the thickness of the circuit from around 1mm down to 100nm thickness. Furthermore, instead of circuit complexities of millions of gates these circuits will involve a handful of elements such as those on the biostamp. Furthermore, when these circuits begin incorporating simple microcontrollers, their only choice for program storage is going to be either read-only memory or one-time programmable, antifuse, non-volatile memory such as supplied by Kilopass Technology.

Both ROM and OTP are ideal for designs that are essentially disposable. Neither require additional manufacturing steps— both use standard logic CMOS, thus neither adds cost to the manufacturing process. Both consume very little power. Where the difference lies, is the requirement that ROM be programmed during the design of the chip and not changeable thereafter. NVM antifuse OTP is programmed during final test, thus allowing one design to be configured at final test into any number of different end products.

These new classes of medical devices will likely create a new type of semiconductor company and new business models to be successful. Besides circuit design and semiconductor manufacturing capability, this new company will require expertise in material sciences mechanical engineering, human physiology, and most important of all, know-how in getting medical apparatus for the human body approved for sale by the Food and Drug Administration. This new semiconductor company will look more like a pharmaceutical enterprise than a chip company.