SHAPE MEMORY SENSOR

• US 20110052116A1
• Filed: 12/24/2008
• Published: 03/03/2011
• Est. Priority Date: 12/28/2007
• Status: Active Grant

• Current Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Original Assignee: Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno
• Inventors: Boersma, Arjen
• Granted Patent: US 9,347,797 B2
• Time in Patent Office: Days
• US Class Current: 385/12
• CPC Class Codes: G01D 5/02 using mechanical means
• CPC Class Codes: G01D 5/35303 using a reference fibre, e.g. interferometric devices
• CPC Class Codes: G01D 5/35316 using a Bragg gratings
• CPC Class Codes: G01K 5/483 using materials with a configuration memory, e.g. Ni-Ti alloys
• CPC Class Codes: G02B 6/02104 characterised by the coating external to the cladding, e.g. coating influences grating properties

Abstract

The invention relates to a sensor for measuring an environmental effect, comprising a sensor material having an internal stress, which sensor material is designed to at least partially relax under the influence of the environmental effect. The sensor further comprising a detection unit for indirectly or directly detecting said relaxation. The invention also relates to a waveguide, comprising a grating in at least a portion of the waveguide, which waveguide comprises a coating, the coating comprising a polymer that contains reversible crosslinks that can be broken by the environmental effect in such a way that the polymer changes shape. The invention further relates to a sensor system comprising a waveguide, a light source, and a photo-detector.

Claims

1. A sensor for measuring an environmental effect, comprising a waveguide having a grating and a coating comprising a sensor material, the sensor material comprising a polymer, the sensor material having internal stress, which sensor material is capable of at least partially relaxing under the influence of the environmental effect, the sensor further comprising a detection unit for indirectly or directly detecting said relaxation.

2. A sensor according to claim 1, wherein the polymer comprises crosslinks, which crosslinks are adapted to be cleaved under the influence of the environmental effect.

3. A sensor according to claim 2, wherein the polymer comprises crosslinks selected from the group of amide group crosslinks, ester group crosslinks, complexed metal ion crosslinks, saccharide-based crosslinks, Diels-Alder-based crosslinks, diazidostilbene-based crosslinks and diperoxide-based crosslinks.

4. A sensor according to claim 1, wherein the sensor material softens and/or changes shape when under the influence of the environmental effect.

5. A sensor according to claim 1, wherein the detection unit is arranged to detect a change in the refractive index of the sensor material.

6. A sensor according to claim 1, wherein the grating is a ‘

long period grating’ and

/or a ‘

fibre bragg grating’

.

7. A sensor according to claim 1, wherein the detection system comprises a light source for sending light into the waveguide and a photo-detector for detecting light leaving the waveguide.

8. A waveguide comprising a grating, the waveguide having a coating, the coating comprising a sensor material as defined in claim 1.

9. A waveguide according to claim 8, comprising a ‘

long period grating’ and

/or a ‘

fibre bragg grating’

.

10-11. -11. (canceled)