mOptical Sensing for the Internet of Things: A Smartphone‐Controlled Platform for Temperature Monitoring

Abstract

Sensors play a key role on the Internet of Things (IoT), providing monitoring inside and outside the networks in a multitude of parameters. A fundamental parameter to sense is temperature, being essential to acquire knowledge on the best way to include thermal sensing into the communications networks. Despite that the temperature measurement in the optical domain is well known for its advantages compared with the electric one, its incorporation in the IoT is a challenge due to the lack of affordable strategies able to convert optical into an electronic signal in a cost‐effective way. The coupling of such optical sensors to smartphones appears as an exciting strategy for mobile optical (mOptical) sensing. Herein, advances in optical temperature sensors for mOptical sensing are reviewed and the chronological mechanistic context of waveguided and nonguided optical signal sensors is outlined. A new path for advances in photonics research is traced, established by the incorporation of smartphones as a tool in science and engineering that foresees new designs for mOptical temperature sensor toward IoT.

Dual-color dynamic anti-counterfeiting labels with persistent emission after visible excitation allowing smartphone authentication

“…Anti-counterfeiting systems that can rely solely on the use of smartphones as that hardware component in an authentication strategy are attractive and convenient as smartphones are ubiquitous 5 , 25 – 29 . However, such systems would need to meet several requirements to permit the reliance on only a smartphone being used and no additional hardware being required for the complete authentication process.…”

Customized Luminescent Multiplexed Quick‐Response Codes as Reliable Temperature Mobile Optical Sensors for eHealth and Internet of Things

“…The recent reports on mobile optical sensing mediated by smartphones appear as an intriguing strategy to enable large‐scale sensing and tracking mediated by the user. [ 10 ] Very few works address simultaneously sensing and tracking, [ 10–13 ] most of the reports focused only on temperature sensing, though photographic records from the luminescent materials recorded with a smartphone or a digital camera. [ 14–16 ] The thermometric parameter relies on the color variation arising from intensity variations.…”

“…From the practical temperature‐sensing point of view, luminescent quick response (QR) codes stand out as smart labels able to provide sensing and allowing the data to be sent over the IoT network, enabling the tracking functionality. [ 10 ] QR codes act as the gateway to IoT due to the growing use of smartphones/mobile devices and their properties such as fast and easy reading, capacity to store more information than that found in conventional codes, and versatility associated with the rapid and simplified access to information. [ 13,37 ] An intriguing example is the use of colored multiplexed luminescent QR codes based on organic−inorganic hybrids (e.g., diureasils [ 38 ] ) modified by trivalent lanthanide (Ln 3+ ) ions.…”

Sustainable Smart Tags with Two‐Step Verification for Anticounterfeiting Triggered by the Photothermal Response of Upconverting Nanoparticles

“…In addition, this approach paves the way for coupling the temperature sensing and colortuning properties to QR codes to develop optical sensors that can be read by smartphones, which is an exciting approach for mobile optical (mOptical) sensing. [35,36] Nevertheless, the use of such an advanced strategy for realworld applications only becomes attractive if one may circumvent dispendious fabrication routes of the QR codes, time-consuming data analysis, and complex implementation. In this way, we herein present a novel method to obtain smart tags by serigraph printing using a sustainable strategy to produce optically active inks using polystyrene (PS) recycled from expanded polystyrene (EPS) package wastes through its dissolution into d-limonene, a green solvent extract from orange peel.…”