Chromogenic humidity sensor

a humidity sensor and chromogenic technology, applied in the field of humidity sensors, can solve the problems of sensor drift, poor durability, impediment to fast response time and good reversibility of sensors,

US20150122017A1Inactive Publication Date: 2015-05-07POSTECH ACAD IND FOUND
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Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
Publication Date
2015-05-07
Estimated Expiration
Not applicable · inactive patent
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Abstract

The present invention relates to a humidity sensor, and more particularly, to a resistance film-type real-time chromogenic humidity sensor produced with a polyelectrolyte thin film. The humidity sensor according to the present invention is a chromogenic hygrometer in which a polyelectrolyte nano thin film that absorbs moisture is formed on a reflective layer, and the nano thin film varies terms of color and electrical resistance as moisture is absorbed and the thickness varies. The hygrometer according to the present invention is a dual-function hygrometer, the color and resistance of which vary. Provided is the chromogenic hygrometer in which the sensor made using a PSS-b-PMB thin film varies in color between purple, blue, green, yellow, orange, and red according to humidity at a very high response speed of within one minute.
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Description

TECHNICAL FIELD

[0001] The present invention relates to a humidity sensor. More particularly, the present invention relates to a real-time, colorimetric resistive-type humidity sensor made of a polymeric electrolyte thin film.BACKGROUND ART

[0002] Chemical sensors based on stimuli-responsive materials have been extensively investigated in past decades. Among a wide variety of target molecules, the accurate and reliable measuring of humidity has attracted great attention in diverse fields including medical science, the food industry, and electronic applications.

[0003] Different types of humidity sensors have been developed from porous ceramics, metals, and polymeric materials, and materials used in these sensors exhibit changes in physical properties such as capacity, resistance, surface acoustic wave, reflection, and fluorescent emission, upon exposure to moisture.

[0004] In the class of humidity-sensitive materials, polymeric materials have particular advantages of flexibility, easy fabri...

Examples

Embodiment Construction

[0060]3D RGB Diagrams of PSS-b-PMB Sensors Under Different Humidities

[0061]At different RHs, the PSS-b-PMB films with different sulfonation levels exhibit characteristic reflection colors, which are plotted inside the 3D cube in FIG. 3. The z-axis shows equilibrium water uptake values of 5 μm thick freestanding films while the sulfonation levels of 240 nm thick PSS-b-PMB films and relative humidities are represented on x-and y-axis, respectively. Filled symbols in the 3D cube represent experimental data while the 3D color surface within the cube was obtained using a Renka-Cline gridding algorithm, which is part of the OriginPro 8.5(R) software package.

[0062]As can be seen in left-front portions of the cube, the PSS-b-PMB films in a dry condition at an RH of 30% appear violet, and undergo a color change with an increase in RH. The thin films with relatively low sulfonation levels change in color from violet to blue while a considerable window of color diagram is occupied by green / yel...