Nano-Anatase TiO2 for High Performance Optical Humidity Sensing on Chip

Abstract

An on-chip optical humidity sensor using Nano-anatase TiO2 coating is presented here. The coating material was prepared so that the result is in solution form, making the fabrication process quick and simple. Then, the solution was effortlessly spin-coated on an SU8 straight channel waveguide. Investigating the sensitivity and performance (response time) of the device revealed a great linearity in the wide range (35% to 98%) of relative humidity (RH). In addition, a variation of more than 14 dB in transmitted optical power was observed, with a response time of only ~0.7 s. The effect of coating concentration and UV treatment was examined on the performance and repeatability of the sensor. Interesting observations were found, and the attributed mechanisms were described. In addition, the proposed sensor was extensively compared with other state-of-the-art proposed counterparts from the literature and remarkable advantages were found. Since a high sensitivity of ~0.21 dB/%RH and high dynamic performances were demonstrated, this sensor is proposed for use in biomedical applications.

Combination of polymeric substrates and metal–polymer nanocomposites for optical humidity sensors

“…Measurement of humidity is important in various fields, such as nuclear reactors, medical equipment, incubators, sterilizers, food industries, civil and aerospace engineering, and paper and textile production . The fabrication of practically applicable humidity sensors with reasonable sensitivity, low hysteresis, acceptable repeatability and reproducibility, linearity in response, and high chemical and physical stability with fast response and recovery time is extremely important.…”

“…To fabricate humidity sensors using an appropriate sensing material that satisfies these requirements is a challenging task. Various humidity sensors based on different principles such as electronic, optical, magnetic, and acoustic have come into existence, and research is in progress to achieve the best possible performance . Out of the above‐mentioned humidity sensor principles, sensors based on electrical measurements are available in the market.…”

Development of a New Humidity Sensor Based on (Carboxymethyl Cellulose–Starch) Blend with Copper Oxide Nanoparticles

“…This shows the need for fast, highly sensitive, and low-cost humidity sensors. Moreover, the fabrication simplicity and low cost are also of importance in humidity sensors [5]. The addition of inorganic nanoparticles to polymers allows a modification of the polymer physical properties, as well as the implementation of new features in the polymer matrix.…”

Magnetoelastic Humidity Sensors with TiO2 Nanotube Sensing Layers

“…A number of methods have been developed for humidity detection, including capacitance [39][40][41][42], resistance [14], optic [43], microwave [44], magnetoelastic [17][18][19], surface acoustic wave [45], and quartz crystal microbalance (QCM) techniques [46,47]. In this study, a magnetoelastic sensor was used to detect humidity.…”