Rotational Pressure-Insensitive Temperature Sensor

The patent employs a bi-metallic strip composed of two metals with different coefficients of thermal expansion (e.g., brass and invar). When temperature changes, the differential expansion causes the strip to bend, which mechanically actuates the capacitance sensor. This thermal expansion mechanism enables temperature sensing while the mechanical coupling inherently isolates the sensing element from direct pressure effects, resolving the contradiction between robustness and pressure sensitivity

The patent replaces traditional electrical temperature sensing mechanisms with a mechanical-biometric system. The bi-metallic strip converts thermal energy into mechanical displacement, which then modulates a capacitance sensor. This mechanical substitution approach allows the sensor to measure temperature through mechanical means that are inherently less sensitive to pressure changes, thereby improving reliability while reducing pressure sensitivity

The patent merges the temperature-to-mechanical conversion function (bi-metallic strip) with the mechanical-to-electrical conversion function (capacitance sensor) into a single integrated device. The bi-metallic strip is directly coupled to the capacitance sensing element, eliminating the need for separate transduction mechanisms. This merging reduces overall device complexity while maintaining high temperature measurement accuracy through the combined biometric-capacitive system

The patent utilizes changes in physical parameters (thermal expansion coefficients, capacitance values) to achieve temperature measurement. By selecting materials with specific thermal expansion characteristics and designing the capacitance sensor with appropriate geometric parameters, the system achieves high measurement precision. The parameter changes approach allows accurate temperature sensing without requiring complex electronic circuitry or multiple sensing elements