Structure and fabrication of a microscale flow-rate/skin friction sensor
AssigneeUniversity of Florida Research Foundation, Inc.
InventorsVijay Chandrasekharan, Jeremy Sells, Mark Sheplak, David P. Arnold
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Abstract
A floating element shear sensor and method for fabricating the same are provided. According to an embodiment, a microelectromechanical systems (MEMS)-based capacitive floating element shear stress sensor is provided that can achieve time-resolved turbulence measurement. In one embodiment, a differential capacitive transduction scheme is used for shear stress measurement. The floating element structure for the differential capacitive transduction scheme incorporates inter digitated comb fingers forming differential capacitors, which provide electrical output proportional to the floating element deflection.
Claims26
A microscale sensor for direct shear stress measurement, comprising:
- a floating element, wherein the floating element comprises a first set of capacitive comb fingers extending from a first side of the floating element;
- at least one tether extending from the floating element for anchoring the floating element to a stationary surface;
- and
- a first set of stationary capacitive comb fingers interdigitated with the first set of capacitive comb fingers of the floating element such that initial gaps between fingers of the interdigitated first set of stationary capacitive comb fingers and first set of capacitive comb fingers are non-uniform.
A microscale sensor comprising:
- a floating element;
- at least one tether extending from the floating element for anchoring the floating element to a stationary surface;
- a comb drive comprising fingers disposed orthogonal to displacement of the floating element, the comb drive being asymmetric for variable gap transduction;
- and
- a cavity disposed below the floating element, the cavity vented for exposure to an ambient.
A method for fabricating a microscale flow-rate/skin friction sensor, comprising:
- performing a first mask process on a front side of a substrate to form a first mask defining sensor features;
- etching the front side of the substrate using the first mask to form sensor features;
- forming a conductive material on the sensor features;
- performing a second mask process on a back side of the substrate to form a second mask defining a backside cavity after forming the conductive material;
- and
- etching the back side of the substrate using the second mask to form the backside cavity.
A method for fabricating a microscale flow-rate/skin friction sensor, comprising:
- performing a first mask process on a front side of a substrate to form a first mask defining all sensor structures;
- and
- etching the front side of the substrate using the first mask as an etch mask to form the sensor structures.
Dependencies are inferred from the claim text.