Self-Powered Pyroelectric Temperature Sensor Using Ferroelectric Polymer and Ionogel
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Solution Overview
Problem
Conventional temperature sensors require external energy sources for operation and cannot continuously monitor temperature, limiting their accuracy and functionality in applications like wearable devices and IoT systems.
Innovation Solution
A self-powered temperature sensor is developed using a pyroelectric layer composed of a ferroelectric polymer and an ionogel, which generates voltage from internal power sources, allowing for accurate absolute temperature measurement without external energy, featuring a Curie temperature range suitable for wearable devices and delayed voltage output for precise temperature sensing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional temperature sensor is used, then it can output voltage depending on temperature changes, but it requires external energy sources and cannot continuously monitor temperature
Solution Approach 1:
The temperature sensor generates its own operating voltage through pyroelectric effect from temperature changes in the measurement target, eliminating the need for external power sources. The sensor serves itself by converting thermal energy into electrical energy for continuous operation.
Solution Approach 2:
The patent utilizes the pyroelectric coefficient of the ferroelectric polymer, which changes with temperature, to generate voltage. By operating near the Curie temperature point where the pyroelectric coefficient is maximized, the sensor achieves high sensitivity and self-powered operation.
2Measurement precision
If a conventional temperature sensor is used, then it can provide temperature data, but it cannot calculate absolute temperature from voltage output alone
Solution Approach 1:
The sensor automatically generates a calibration curve by measuring voltage at known temperature points during manufacturing, storing this data internally. This self-calibration capability eliminates the need for external calibration equipment and enables absolute temperature calculation from voltage output.
Solution Approach 2:
The calibration data is prepared in advance during the manufacturing process, creating a lookup table or mathematical model that allows the sensor to directly calculate absolute temperature from voltage measurements during operation without requiring complex real-time computations.
3Speed
If the temperature sensor responds quickly to temperature changes, then it provides real-time data, but it may miss delayed voltage output at constant temperatures
Solution Approach 1:
The patent employs a dual-mode measurement approach: for dynamic temperature changes, it captures voltage signals in real-time to track temperature variations; for constant temperatures, it uses the delayed voltage output from the ionogel's ionic relaxation to achieve precise measurements. The system dynamically switches between modes based on the thermal conditions.
Solution Approach 2:
The ionogel layer provides continuous voltage output even when temperature stabilizes, due to the slow ionic relaxation process. This continuous signal allows the sensor to maintain measurement capability during constant temperature periods, complementing the rapid response during temperature transitions.
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 sensor achieves high accuracy in measuring absolute temperature and temperature changes over time, even at constant temperatures, without external power, enhancing its suitability for wearable devices and IoT applications by leveraging the pyroelectric properties of the ferroelectric polymer and ionogel combination.
Implementation Method 1
a pyroelectric layer between the first electrode and the second electrode and including a ferroelectric polymer and an ionogel
Implementation Method 2
A Curie temperature of the ferroelectric polymer may be about 60° C. to about 140° C.
Data Source
AI summary
A temperature sensor includes a first electrode, second electrode, and a pyroelectric layer between the first electrode and the second electrode. The pyroelectric layer includes a ferroelectric polymer and an ionogel.