Apparatus for assessing a particular property in a medium
First Claim
1. An apparatus for assessing a particular property of a medium comprising:
- a chamber having a thermally conductive portion;
a vibratile element thermally coupled within said chamber to said thermally conductive portion;
optical excitation means for delivering optical excitation energy incident to said vibratile element so as to cause the vibratile element to vibrate at its resonant frequency without inducing thermal changes in the chamber;
optical means for monitoring and detecting the vibration frequency of the vibratile element; and
thermally activated sensor means, thermally coupled to an exterior surface of said thermally conductive portion thereby being exposed to enable contact between said thermally activated sensor means and the medium, said thermally activated sensor means being a material which is thermally activated when contacted with said medium having said particular property for changing the temperature of the chamber and hence the resonant frequency of the vibratile element by heat transfer through the thermally conductive portion between the thermally activated sensor means and the chamber, said changes in said resonant frequency being monitored and detected by the optical means which provides an assessment of the presence of said particular property of said medium.
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Accused Products
Abstract
A sensor is provided which is sensitive to a particular property of a medium and which is thermally activated when in contact with the property containing medium. The sensor is externally mounted on the undersurface of a silicon wafer, the upper surface of which contains a well in which a vibratile bridge element is located. The top of the well is closed off so that the vibratile bridge element is within a chamber. Excitation energy from a source is delivered to the vibratile bridge element to establish vibratory motion which is monitored and detected by a circuit. Presence of the particular property in the medium causes a thermal change in the wafer resulting in a change in the resonance frequency of the vibratory motion of the vibratile bridge element. The frequency shift is a measure of the particular property.
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Citations
6 Claims
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1. An apparatus for assessing a particular property of a medium comprising:
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a chamber having a thermally conductive portion; a vibratile element thermally coupled within said chamber to said thermally conductive portion; optical excitation means for delivering optical excitation energy incident to said vibratile element so as to cause the vibratile element to vibrate at its resonant frequency without inducing thermal changes in the chamber; optical means for monitoring and detecting the vibration frequency of the vibratile element; and thermally activated sensor means, thermally coupled to an exterior surface of said thermally conductive portion thereby being exposed to enable contact between said thermally activated sensor means and the medium, said thermally activated sensor means being a material which is thermally activated when contacted with said medium having said particular property for changing the temperature of the chamber and hence the resonant frequency of the vibratile element by heat transfer through the thermally conductive portion between the thermally activated sensor means and the chamber, said changes in said resonant frequency being monitored and detected by the optical means which provides an assessment of the presence of said particular property of said medium. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification