The world of spectroscopy has long been dominated by large scientific companies who make incredibly sensitive and accurate instruments for work in laboratories. As computing power has become pervasive, with most people carrying smartphones, it’s now possible to bring some of this functionality directly to consumers. The missing link are sensors that are small, low power, and accurate enough to be deployed in mobile phones or other handheld devices.
Currently, these systems are designed discretely with an optical front end, A/D converters, a high-end microprocessor, an integrated light source, and signal-processing algorithms optimized for lab applications. Spectral filters, photo diode technology, and low-noise analog front ends are key in such systems, as is the ability to control the light source. Using on-chip interference filters and a photo diode array, up to six unique filters can be optimized for any application. With sub-micron mixed-signal CMOS technology with integrated silicon photonics, all of these components can be integrated onto one chip that enables a high-performance system in a small handheld device or mobile phone. Sensors can then be optimized to focus on a key set of applications, enabling a cost-effective system for wide deployment to consumers.
One way “consumerization” of spectral applications can occur is by employing six-channel spectral identifications and classification products, known as Spectral_ID devices. One such product, a visible (VIS) device can look into the color space and provide twice as much information as current RGB sensors, from 380 nm to 680 nm. The near Infra-red (NIR) device is sensitive to wavelengths from 600 nm to 1,000 nm in the same detail. In the future, we’ll be sensing at wavelengths beyond the capability of silicon, with cost-effective technologies.
These advanced Spectral_ID sensors will become part of the Internet of Things (IoT) as they interface to the cloud infrastructure. In turn, they’ll access spectral or digital health libraries and link via wireless signals to your smartphone to provide real-time information. Applications could include food and water safety, authentication of everything from bank notes to pharmaceuticals, and biosensing to monitor your health and advise if some monitored parameters are out of their normal range.
While today’s consumers have these needs, no solutions are available. Spectral sensing devices are being created as accessories are integrated directly in the phone or as a wearable device, spawning new services, applications, and business models. Companies will use these intelligent sensors integrated with cloud services as another way to interact with consumers, creating brand loyalty and to ensure an excellent consumer experience. Insurance providers will use them to take costs out of our health care system and improve patient treatments and outcomes.
Paul Wilmarth has over 25 years in the semiconductor industry supporting consumer electronics, mobile, medical, and industrial. At ams, he helps develop spectral sensing products for such markets as authentication, currency validation, biosensing, and food safety.