Photonic humidity integrated sensor based on hybrid polymer/cobalt chloride systems

Tsigara, A; Mountrihas, G; Mousdis, G; Pispas, S; Madamopoulos, N; Vainos, N

dc.contributor.author	Tsigara, A	en
dc.contributor.author	Mountrihas, G	en
dc.contributor.author	Mousdis, G	en
dc.contributor.author	Pispas, S	en
dc.contributor.author	Madamopoulos, N	en
dc.contributor.author	Vainos, N	en
dc.date.accessioned	2014-03-01T02:50:11Z
dc.date.available	2014-03-01T02:50:11Z
dc.date.issued	2005	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/34936
dc.subject.other	Anionic polymerization	en
dc.subject.other	Cobalt compounds	en
dc.subject.other	Crystal structure	en
dc.subject.other	Diffraction gratings	en
dc.subject.other	Polyethylenes	en
dc.subject.other	Spin coating	en
dc.subject.other	Cobalt chloride systems	en
dc.subject.other	Hybrid polymers	en
dc.subject.other	Photonic humidity integrated sensors	en
dc.subject.other	Optical sensors	en
dc.title	Photonic humidity integrated sensor based on hybrid polymer/cobalt chloride systems	en
heal.type	conferenceItem	en
heal.identifier.primary	10.1109/CLEOE.2005.1568248	en
heal.identifier.secondary	http://dx.doi.org/10.1109/CLEOE.2005.1568248	en
heal.identifier.secondary	1568248	en
heal.publicationDate	2005	en
heal.abstract	Hybrid materials composed of cobalt chloride nano- and microcrystals incorporated in polymer matrices were evaluated as humidity sensors and incorporated in integrated photonic devices. The structures were fabricated by spin coating of polymer/ CoCl2 on glass substrates. Composite grating structures were also fabricated using this material. The materials were prepared by wet mixing of high purity laboratory homopolymers mainly poly(ethylene oxide), synthesized by high vacuum anionic polymerization with CoCl2 The thickness of the films was in the range 100nm-250nm. Grating structures thickness range between 1 μm and 1,5 μm. In contrast to the well known cobalt chloride chromatometric response1,2 no significant absorbance shift was observed upon exposure to humidity. The response of the materials is mainly attributed to reversible surface morphology and molecular complex modification. These, affect the transmission characteristics either due to random scattering, or due to the alteration of the optical grating morphology. In the latter case a model is proposed for the redistribution of the incident optical energy on the various diffraction orders upon humidity variation based on refractive index and surface profile modifications. The optical design is based on transmittance and diffraction meassurements, and incorporates a monochromatic optical source and optoelectronic detection components. The advantageous characteristics of the presented integrated sensor are the fully reversible behaviour, at ambient operating conditions, without the need for additional heating or light exposure. The response time to humidity variations is less than a second as measured at the available humidity exposure rate. The films were examined for long term stability and proved to be accurate and functional for several months. © 2005 IEEE.	en
heal.journalName	Conference on Lasers and Electro-Optics Europe - Technical Digest	en
dc.identifier.doi	10.1109/CLEOE.2005.1568248	en