IoT Unlocks New Markets for Compact Optical Sensors

Marie Freebody, Contributing Editor, marie.freebody@photonics.com

It’s a complex, technology-mixing ecosystem that combines sensors, IT and networking technologies to enable billions of devices to be connected around the world.

On a typical day, you may not even realize the plethora of smart technology permeating our homes, cars, offices, shops, hospitals and cities — from the smartphone you may be reading this article on and the smartwatch that tells you when you need to leave for work to make it in on time, to the smart coffee maker that helps kick-start your day.

Viavi Solutions contributes innovative technologies (purple) to modern smartphones. Contributions include proximity sensors; a camera (today’s phones can feature up to 3 cameras); ambient light RGB hue, including sensors that can drive the brightness and color balance of the display and can also be used to adjust the white balance of the camera to account for ambient light conditions; and a fingerprint sensor/camera. Courtesy of Viavi Solutions.

On the move, smart traffic monitors help ease you along your journey as swiftly as possible. At the office, heating and cooling is taken care of and depleted stationery is automatically re-ordered. While on a break, you may be checking who has visited your home thanks to facial recognition security cameras. And at the end of the working day, when your thoughts turn to what you might need to pick up on the way home, the Samsung Family Hub fridge is just a click away — you can check your fridge contents via its built-in camera or simply access the shopping list it keeps for you to ensure you never run out of anything.

New multifunction, intelligent sensors from Excelitas detect and monitor multiple environmental parameters simultaneously from a single, compact unit to meet ever-shrinking space requirements and better enable expanding applications of the IoT. Courtesy of Excelitas Technologies.

Finally, unwind in front of a smart television — or even a regular television using a set-top box or special dongle — that allows you access to the whole range of online services. And when you go to bed, don’t forget to switch your lights off using wireless lighting.

The Internet of Things (IoT) is all around us, and this is just the beginning. IoT is primed to change our lives and businesses in ways we can’t yet imagine. Technology companies from the biggest players to the smallest component makers are looking at ways to enhance their products and invest in the IoT trend.

The interferometer in the Renewable Energy Analysis (REAL) Lab can be operated remotely from any location around the world. Courtesy of Rami Saarikorpi.

Smart sensors already in place

According to the market research company Yole Développement of Lyon, France, multiple connected sensors, including infrared, air quality, visible imagers, smart thermostats and associated services, are vital for energy savings and increased security in the smart homes and buildings of the future.

Viavi’s Multispectral Sensor Chip features Viavi’s 64-channel micro-patterned bandpass filter array. Courtesy of Viavi Solutions.

While much of today’s optical technology is already suitable for incorporating into an IoT device, Yole points out that it is a chicken-and-egg problem — usually the technology is there but the application has to drive significant volume for the technology to be matured.

“The 3D semiconductor is opening a grand new field of innovation for photonics, but someone has to invest in the technology before any significant volume is visible. Being the first is sometimes a difficult task,” said Yole’s activity leader of Imaging, Pierre Cambou. “In the end, it is again a question of cost, performance, energy consumption, and packaging and integration.”

One thing is clear: Smart sensors will become the backbone of a variety of applications from communications, the automotive industry and manufacturing, to logistics and health care.

Infrared sensing technologies such as Excelitas’ low-power DigiPyro smart detectors streamline integration and permit extended remote operation in IoT products. Courtesy of Excelitas Technologies.

As smart technologies move toward practical use in homes, many OEMs are looking for ways to pack more technology and functionality into smaller devices — requiring smaller optical components and designs that are “slick” enough for the systems to become almost invisible.

At Excelitas Technologies of Waltham, Mass., its range of infrared sensing technologies for the IoT market focus on gauging dynamics such as motion and temperature including its DigiPyro Smart Detectors for motion detection and the DigiPile Thermopile Sensors for temperature measurement.

Combining motion detection, presence detection and temperature measurement in one package is the CaliPile Multifunction Infrared Sensor, which Wolfgang Schmidt, senior product manager of IR Sensing, says is the latest addition to its range of infrared sensing technologies.

Products such as Excelitas’ new CaliPile IR sensors detect motion, sense presence and measure temperature functions all in one compact component to meet IoT market demands for multipurpose infrared detectors. Courtesy of Excelitas Technologies.

Bosch Sensortec GmbH, part of the Bosch Group, offers a range of sensors and solutions for mobile devices. For example, its environmental sensors have been developed to support a broad range of emerging high-performance applications such as indoor navigation, home automation control, personalized weather stations and innovative sport and fitness applications for measuring gas, pressure, humidity and temperature, all in a single device.

Smart sensors + smart lighting

The number of households is growing twice as fast as the number of people worldwide, which means twice as many resources are needed for lighting, heating and cooling. Moreover, security and wellness are also becoming increasingly important to the people living in these homes.

Recognizing the trend is lighting giant Philips Lighting, headquartered in Eindhoven, the Netherlands. The company has increasingly shifted from the manufacturing of traditional lighting products to developing connected lighting systems and services that work within the IoT to deliver value beyond illumination, including social and economic benefits.

“The world needs more light, better energy-efficient light and digital, connected lighting in order to support the growth in the global population and urbanization and mitigate the impact to the planet,” said Tim Schenk, R&D group manager of Home Systems at Philips.

Launched in 2012, the company’s Philips Hue connected lighting system enables wireless control of home lighting from a smartphone, tablet, smartwatch, smart switch, the Philips Hue motion sensor and voice platforms such as Amazon Alexa, Apple HomeKit and Siri, and Google Home and Google Assistant.

With the Philips Hue app, a smart switch, the Philips Hue motion sensor or your voice, you can turn your lights on and off, dim to the desired brightness for a perfect ambiance and even recall pre-set scenes, change colors and more. Courtesy of Philips Lighting.

The right shade of bright light can be selected when studying or working, or a warm, amber-toned light can be set to help you relax in the evening and wind down for sleep. What is more, smart lighting can be used to create an immersive entertainment experience by syncing the lights with music, movies or games.

“The lights integrate LEDs of different colors, and we apply different optical designs to mix the light to create the desired light output,” Schenk said. “This is specifically challenging in spotlights, like our GU10 products, due to their small size. We need to combine good (uniform) color-mixing with creating a narrow beam.”

Currently, Philips Hue also works with Bosch, Nest, Samsung SmartThings and many other smart home devices. Looking to the future, the company encourages other manufacturers to develop devices, apps and systems that interoperate with its connected lighting system.

In terms of technological progress, Schenk points out that further integration of LEDs and other electronic components will allow for more lighting products to be connected, and to be controlled in terms of the light level and color-tunability.

“Optical component improvements could also help control the direction of the light. Additionally, the integration of sensors in lights will be required to support new applications. This could enable home lighting to adjust itself automatically to [match] certain contexts whether you are reading, playing games or socializing with friends,” he said. “This will pose new design challenges to balance wireless and optical performance. New optical design solutions will need to do more than hiding the antenna.”

Viavi Solutions, formerly JDS Uniphase, is a Milpitas, Calif.-based technology company. As well as creating testing and monitoring equipment for networks, the company develops optical technology for a range of applications including IR filters for cameras.

The company’s focus is on the smartphone space, developing low-angle shift optical filters that allow a wide field of view for very small form factor sensing and imaging subsystems.

“The market for IoT is seeing some headwinds where it is implemented in distributed devices — for example, smart thermostats, lighting automation, robotic vacuums,” said Markus Bilger, product line manager at Viavi Solutions. “Where we are seeing the most progress is the smartphone, which is at the core of the system.”

In smartphones and other electronic devices, Viavi’s filters transmit the light emitted by a near-IR LED or laser and suppress all other wavelengths for 3D depth sensing/imaging in biometric, gesture and VR/AR applications; proximity sensing; and autofocus assist with time-of-flight capabilities to measure distance and improve camera performance.

Smartphones also contain ambient light sensors where optical filters are used to mimic the human eye response so that the display brightness can be adjusted depending on ambient light conditions. This makes the display more readable and saves battery power. Multiple filter coatings including RGB filters and occasionally IR bandpass filters and/or UV filters are used to sense color to drive color balance of the OLED display or in conjunction with a world-facing RGB camera to adjust the white balance of pictures.

“Optical filters work in conjunction with active illumination for maximum light collection efficiency and high signal-to-noise ratio,” Bilger said. “The challenge is finding ways to make these optical systems as immune as possible to harsh ambient light conditions. Improvements need to be made to optical components so that the smallest possible form factor provides the lowest possible angle dependency.”

The IoT market, today and tomorrow

There is a growing trend for the IoT, but as Eric Mounier, Ph.D., senior technology and market analyst of MEMS and Sensors at Yole, suggests, the size of the market will probably not fulfill the 50 billion devices in 2020 that Cisco envisioned¹.

“There is a trade-off between 50 billion devices costing $10 and 500 million devices at $1000. This is a lot of business to be generated — consumer electronics is $1.2 trillion — in a slow-growing economy,” Mounier said.

The trend exists for connected devices, but at the same time, device convergence reduces the number per person: Today’s smartphone now performs the job of a camera, MP3 player, digital assistant, heath monitor, game console, GPS, TV, computer and telephone, in a single device.

According to Yole’s 2015 report, “Sensors for Wearable Electronics and Mobile Healthcare²,” the wearable industry was originally supposed to reach 295 million units by 2020, with a market value of $95 billion. However, a consumer market slowdown, half-baked products and a lack of relevant applications has limited the popularity of wearables and reduced the potential value of this market in 2020.

IoT devices: Where and how many?

In 2017, the number of IoT devices will approach 6 billion — and growth is high, around 10 percent. This growth is a cumulative process. Most devices last more than five years — with the exception of smartphones, which have a replacement cycle on the order of two years.

Below is a breakdown of devices (“installed base” is the number of devices in use):

• Mobile phones — around 3.5 billion units (installed base)

• Computers and tablets — around 2 billion units (installed base)

• Smart factory and logistics — around 200 million (installed base)

• Wearables — around 100 million units

• Connected home/home robotics — around 100 million units (installed base)

• Smart infrastructure and smart health care — a few tens of millions

Looking ahead, better-adapted wearable devices will drive the market, while building/home automation, industry and the environment will also make up an increasing part of the IoT landscape. Two other IoT market segments should also drive growth: health care and industry.

“The health care market including hearing aids, blood pressure monitors, [and] back monitor sensors is expected to grow at a moderate rate,” Mounier said. He also said the industrial market will see “steady growth through to 2019, with a significant uptick commencing in 2020.”

References

1. D. Evans (2011). The internet of things: How the next evolution of the internet is changing everything. Cisco, white paper, pp. 2-11.

2. Yole Développement (2015). Sensors for wearable electronics and mobile healthcare, pp. 1-291.

The smart, virtual laboratory

You may have heard of augmented reality and virtual reality claiming the time of many an avid gamer, or being used by surgeons to practice complex operations, but these worlds exist only on a computer. You may not have heard of the Sm4rtLab, which has opened its virtual laboratory to scientists and students, enabling them to operate research equipment remotely.

A screenshot of the Sm4rtLab web user interface. Courtesy of University of Eastern Finland.

Developed at the University of Eastern Finland, the Sm4rtLab can be used for teaching and research from anywhere in the world. With the goal of merging the worlds of theoretical and experimental research, Sm4rtLab provides realistic-looking modeling, and the physical measurements in the background can come from a real or a simulated device.

“The Internet of Things is bringing de facto standardization to laboratory equipment and sensor connectivity, data collection and analysis,” said professor Pasi Vahimaa. “We will be able to speed up the ramp-up of a research project from months to weeks when using standardized approaches utilizing the IoT ecosystem and the Sm4rtLab concept.”

Professor Pasi Vahimaa conducts an experiment using an interferometer in the virtual Sm4rtLab, which carries out the experiment and feedbacks the results. Courtesy of Rami Saarikorpi.

Research groups can pick suitable sensors and devices from a catalogue, after which the university’s IT services can take care of the IoT setup, thus leaving researchers more time to do actual research. According to CIO Juha Eskelinen, there are a large number of components that are already practically IoT-ready.

“We are currently utilizing a control PC with LabView as a front interface which in turn is connected to the optical components,” Eskelinen said. “This PC is then acting as a gateway toward the IoT cloud, so it is not a problem to connect to components. The remaining part is mostly applying basic robotics to enable physical movement of the components without connectivity.”

The most challenging part is the use of advanced scientific devices in which the control systems are too often proprietary and closed. Fortunately, Eskelinen notes that companies are starting to open their access protocols to enable better connectivity.

“In the future, we are confident that components will be able to connect directly to the IoT cloud,” he said. “We have created Sm4rtLab as an open concept and hope that it will spread to as many laboratories around the world as possible.”