Elaboration and characterization of novel humidity sensor based on micro-carbonized bamboo particles

In this work, eco-friendly, low cost and efficient humidity sensors were prepared from micro-sized pyrolyzed bamboo. Two types of pyrolyzed particles were investigated: as such carbonized bamboo (CB) and annealed ones (CBA). After pyrolysis, the materials were first manually ground and then, attrition milled. The synthesized particles were characterized by using field emission-scanning electron microscopy (FESEM), Raman spectroscopy, specific surface area (SSA) measurements and thermogravimetric analysis (TGA). The sensing materials were screen-printed onto commercial α-alumina substrates with platinum electrodes prior to firing at 300°C for 1 h. The humidity sensing characteristics of the pyrolyzed bamboo based sensors were investigated at room temperature in the relative humidity (RH) range from 0.0 to 96.0%. The pyrolyzed bamboo based humidity sensors exhibited an excellent response towards humidity starting from 10% RH, while CBA showed a response starting from 20% RH. Finally, the response and recovery times were reasonably fast (less than 2 min).