Duke University

Tyrata, Inc.

Joseph Batton Andrews

Aaron Franklin

Martin Brooke

Ashutosh Chilkoti

David Alan Koester

Benjamin B Yellen

Angus Hucknall

Steven Cummer

Daniel Joh

James Barton Summers, Iii

Roozbeh Abedini-Nassab

Martin Anthony Brooke

Methods of measuring a thickness of a material are disclosed. An oscillating signal at a measurement frequency is applied to a circuit including an inductive component and a capacitive component provided using a pair of capacitive sensor electrodes adjacent the material. The measurement frequency is less than a resonant frequency of the circuit, and the resonant frequency is based on the inductive component and the capacitive component. Information regarding a value of a measured parameter is generated based on applying the oscillating signal at the measurement frequency to the circuit. A value of the measured parameter is related to the thickness of the material.

Methods providing enhanced material thickness sensing with capacitive sensors using inductance-generated resonance and related devices

Disclosed are sensors that include a carbon nanotube channel and a non-fouling polymer layer, where the non-fouling polymer layer and the carbon nanotube channel do not directly contact each other and are separated by a dielectric layer. The disclosed sensors may be used, e.g., as biosensors for the accurate and sensitive detection of analytes within a sample. Also disclosed are methods of making and using the sensors.

Nonfouling biosensors

A method of measuring thickness of a material generally includes applying an oscillating signal to a first electrode at a fixed frequency, passing the signal through the material to a second electrode, and measuring the magnitude of the signal reflected back to the first electrode. The thickness of the material is determined based on the measured magnitude of the reflected signal by: 1) comparing the determined magnitude to a predetermined baseline to establish a difference; and 2) identifying the thickness based on the difference. Related apparatuses are also disclosed. The material may be a vehicle tire.

Non-invasive thickness measurement using fixed frequency

Methods of measuring thickness of a material using cross-capacitance. The method generally includes applying a time-varying signal to a first pad and monitoring a response of a capacitor formed by the first pad, a spaced apart second pad, and the material. The pads may be permanently affixed to the material, in spaced relation to each other. Based on the response, a capacitance of the capacitor is determined. The material may be homogenous or heterogeneous, and has dielectric properties. Because the material acts as a dielectric, the capacitance of the capacitor changes as the thickness of the material changes. Thus, the thickness of the material may be determined based on the determined capacitance. The method may be advantageously employed to measure the thickness of a vehicle tire or other material. Related apparatuses are also disclosed.

Non-invasive thickness measurement using capacitance measurement

A method of measuring thickness of a material generally includes transmitting an oscillating signal from a first pad, through the material, to a second pad, and measuring the signal reflected back to the first pad. The material may be homogenous or heterogeneous, and has dielectric properties. The signal has its frequency varied over time so that the frequency response of the system (the first pad, the material, and the second pad) may be analyzed. The resonant frequency of the system is determined. The thickness of the material is determined based on the resonant frequency shift caused by a change in thickness of the material. The present invention may be advantageously employed to measure the thickness of a vehicle tire or other material. Related apparatuses are also disclosed.

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Durham, NC, United States of America

Joseph Batton Andrews