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

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. Temperature sensors play a key role on the Internet of Things, being essential to acquire knowledge on the best way to include them into this network. Herein, the advances in optical temperature sensors are reviewed, emphasizing nonwaveguiding optical sensors based on smart materials that when coupled to smartphones appear as an exciting strategy for mobile optical sensing.