RGO-Ni Composite Cryogenic Temperature Sensor
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Solution Overview
Problem
Conventional cryogenic temperature sensors face limitations such as high current consumption, self-heating, and the need for individual calibration, making them costly and impractical for sensitive and dynamic temperature applications.
Innovation Solution
A reduced graphene oxide-nickel (RGO-Ni) composite based cryogenic temperature sensor is developed, featuring a composite film deposited on a substrate with a constant current consumption of 1 μA across all temperature bands, eliminating self-heating and requiring no variable current source or individual calibration, and exhibiting resistive thermal switching at temperatures below 100K.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional temperature sensors (silicon diode, RTD, thermocouple) are used for cryogenic temperature measurement, then temperature sensing capability is achieved, but high current consumption and self-heating occur leading to measurement errors
Solution Approach 1:
The patent employs a composite material consisting of reduced graphene oxide (rGO) and nickel nanoparticles. The rGO provides a base structure with low electrical resistance, while the nickel nanoparticles dispersed within it create additional conduction pathways and enhance the temperature coefficient of resistance. This composite structure achieves high temperature sensitivity without requiring high measurement currents, thereby eliminating self-heating effects and improving measurement accuracy at cryogenic temperatures.
Solution Approach 2:
The patent utilizes the change in electrical resistance parameters of the rGO-Ni composite material with temperature. By optimizing the concentration and distribution of nickel nanoparticles within the rGO matrix, the material exhibits a significantly enhanced temperature coefficient of resistance compared to conventional materials. This parameter change allows for highly sensitive temperature measurement using minimal current, resolving the contradiction between measurement precision and energy consumption.
2Adaptability or versatility
If NTC RTDs like CERNOX are used for wide temperature range measurement, then temperature sensing over broad range is achieved, but individual calibration is required for each device increasing cost and complexity
Solution Approach 1:
The patent employs a homogeneous distribution of nickel nanoparticles within the reduced graphene oxide matrix, created through a controlled chemical reduction process. This homogeneous composite structure ensures consistent electrical and thermal properties across different sensor batches. The uniformity of the material composition leads to reproducible temperature-resistance characteristics, eliminating the need for individual calibration of each sensor device while maintaining wide temperature range capability.
Solution Approach 2:
The patent creates a standardized sensor design with fixed geometric parameters and controlled material composition. By establishing a reproducible fabrication process that copies the same rGO-Ni composite structure across all devices, the patent achieves interchangeability without calibration. Each sensor is essentially a copy of the optimized design, ensuring consistent performance across the wide temperature range from 4K to 300K.
3Measurement precision
If PTC RTDs are used for accurate temperature reading, then measurement accuracy is improved, but high current consumption and self-heating occur
Solution Approach 1:
The patent fundamentally changes the electrical resistance parameter characteristics by using a negative temperature coefficient material (rGO-Ni composite) instead of positive temperature coefficient materials. The composite material exhibits decreasing resistance with increasing temperature, allowing for accurate temperature measurement using very low currents. This parameter change eliminates the self-heating problem inherent in PTC RTDs while maintaining high measurement precision through the material's sensitive resistance-temperature relationship.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The RGO-Ni composite sensor provides high sensitivity, low power consumption, and standard temperature response, enabling accurate and efficient temperature measurement across a wide range, suitable for cryogenic applications without the need for clean room facilities, thus being more economical and versatile.
Implementation Method 1
the temperature sensor exhibits TCR ranging from 17.48×10−3/K to −148.10×10−3/K. In an embodiment, the temperature sensor exhibits TCR of −147.37×10−3/K for a temperature below 10K
Implementation Method 2
exhibiting resistive thermal switching at temperatures below 100K
Data Source
AI summary
The present disclosure generally relates to the field of resistive sensing. In particular, the present disclosure relates to a highly sensitive reduced graphene oxide-nickel (RGO—Ni) composite based fast response temperature sensor. Aspects of the present disclosure provide a method for fabrication of a highly sensitive reduced graphene oxide-nickel (RGO—Ni) composite-based temperature sensor. An aspect of the present disclosure provides a temperature sensor comprising: a substrate; and a composite film deposited onto said substrate, wherein the composite film comprises a reduced graphene oxide-nickel composite film. In an embodiment, the temperature sensor is cryo-compatible.