Duke University

Martin Brooke

Aaron Franklin

Joseph Batton Andrews

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.

Growing community of inventors

Hillsborough, NC, United States of America

Martin Brooke