Humidity sensors polyethylene

Fig. 8.3. (Left) Solid state OECT humidity sensor printed on polyethylene-coated paper. (Right) The sensor was capable of operating when bent at a radius of curvature of approximately 5 cm. Reprinted from [9] with permission from Elsevier...

Sakai, Y, Rao, VL., Sadaoka, Y, and Matsuguchi, M. (1987). Humidity sensor composed of microporous film of polyethylene-graft-poly-(2-acrylamido-2-methyl-propane sulfonate). Polym. Bull. 18 501. 

Sakai, Y, Sadaoka, Y, Matsuguchi, M., Rao, VL., and Kamigaki, M. (1989). A humidity sensor using graft copolymer with polyelectrol3de. Polymer 30 1068. Sakai, Y. and Sadaoka, Y. (1985). Humidity sensors using sulfonated microporous polyethylene films. Denki Kagaki 53 150. 

Intensive research effort has been focused on using nanoscale structures to significantly improve the performances (sensitivity, selectivity, response and recovery speed) of the SAW sensors. Liu et al. [39] reported that dynamic chemical vapor SAW sensors have been developed by depositing electrospun polyethylene oxide nanofibrous membranes on the surface of ST-cut quartz the response time of the sensors was 5 min (Fig. 11.2a). Lin [42] constructed a SAW humidity sensor by casting polyaniUne/poly(vinyl butyral) nanofibers on SAW resonator the as-prepared sensor could detect 0.5 % relative humidity in 1 s. Electrospun poly(vinyl pyrrolidone) (PVP)/LiTa03 composite nanofibrous membranes were coated onto the surface of SAW electrode to assay H2 the results indicated that the sensors sensitivity, response time, and recovery time could be remarkably improved and reached 1 %, 120, and 200 s by regulating the electrospinning parameters [43]. 

Resistance-humidity characteristics of a swelling-type sensor consisting of polyethylen-oxide-sorbitol. 

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