Temperature sensor for tracking body temperature based on printable nanomaterial thermistor

Inventors

SUN, Caiming • Chen, Xiaohua

Assignees

Nano and Advanced Materials Institute Ltd

Abstract

Provided are wireless temperature sensors. A temperature sensor with a flexible, large-area printed thermistor can include an negative temperature coefficient (NTC) thermistor for temperature sensing, a control circuitry for electrically connecting with the NTC thermistor and obtaining the temperature sensed by the NTC thermistor, a power source for providing power supply to the NTC thermistor and the control circuitry, and a frame element for supporting the NTC thermistor, the control circuitry and the power source, where the frame element is at least partially thermally insulated to establish thermal equilibrium within the temperature sensor. The temperature sensor can sense the temperature in a fast and accurate way due to fast thermal equilibrium established within the sensor.

Core Innovation

The invention provides a temperature sensor based on a printable NTC thermistor, where the NTC thermistor includes a substrate, a Si-C film printed on the substrate, and printed electrodes on the substrate for connecting the Si-C film with control circuitry. The NTC thermistor further comprises a first laminate and a second laminate arranged relative to the Si-C film and the electrodes to address thermal curing and moisture resistance.

The first laminate is directly arranged on the Si-C film and the electrodes and is configured to improve thermal curing of the NTC thermistor, while the second laminate is arranged on one side of the first laminate opposite to the Si-C film and the electrodes and is configured to prevent moisture from penetrating into the NTC thermistor. The sensor includes control circuitry for obtaining the temperature sensed by the NTC thermistor and a power source for supplying power to the NTC thermistor and the control circuitry.

The temperature sensor further includes a frame element that supports the NTC thermistor, the control circuitry, and the power source, where the frame element is at least partially thermally insulated to establish thermal equilibrium within the temperature sensor. In wireless embodiments, the sensor additionally includes a wireless module that receives sensed voltage from the control circuitry and sends the sensed voltage wirelessly, with control circuitry comprising a constant current driving circuit and a measurement circuit that determines sensed voltage based on constant current and the resistance of the NTC thermistor.

Claims Coverage

The partial content provides two independent claims, one for a general temperature sensor and one for a wireless temperature sensor. Across these claims, the inventive features are centered on a printable Si-C/NTC sensing element with two laminates for curing and moisture penetration, constant-current sensing with resistance-based voltage determination, and a thermally insulated frame for thermal equilibrium, with an added wireless module in the wireless claim.

The independent claims collectively cover a printable Si-C based NTC thermistor with a laminate stack that improves thermal curing while preventing moisture penetration, combined with control circuitry and power supply, and a frame element that is at least partially thermally insulated to establish thermal equilibrium. The wireless independent claim additionally requires constant-current driving with a measurement circuit that determines sensed voltage from constant current and thermistor resistance, plus a wireless module that transmits the sensed voltage.

Stated Advantages

Documented Applications