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

Sensors

Mahdiar Ghadiry²  Mehrdad Gholami¹  Lai Choon Kong²  Chong Wu Yi²  Harith Ahmad²  Yatima Alias¹ 

[1] Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603, Malaysia;Photonics Research Center, University of Malaya, Kuala Lumpur 50603, Malaysia;

关键词: humidity sensing;    nano-anatase TiO₂;    waveguide;    evanescence field;    optic sensor;   

DOI  :  10.3390/s16010039

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.