Unpowered Radiation Sensor Using Oscillating CMOS Circuit
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Solution Overview
Problem
Existing radiation sensors require a power supply to function and cannot accurately measure radiation exposure when unpowered, limiting their application in scenarios where power is not available, such as in medical or food safety applications.
Innovation Solution
A radiation sensor device integrated with a radiation-sensitive cell that varies resistance in response to incident radiation, allowing it to oscillate and count radiation exposure events even when unpowered, using a CMOS circuitry that includes an EEPROM cell, MOSFET transistor, capacitor, and comparator to deliver a signal and track radiation exposure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing radiation sensors are used, then radiation detection function is achieved, but power supply is required which limits application scenarios
Solution Approach 1:
The radiation sensor device measures radiation exposure during irradiation without requiring an external power supply. The sensor utilizes the radiation energy itself to generate the measurement signal, making the system self-powered during operation. This is achieved through a radiation-sensitive cell that converts incident radiation directly into electrical signals for measurement.
Solution Approach 2:
The patent employs an oscillating circuit that generates periodic signals whose frequency is modulated by the radiation-sensitive cell. The radiation exposure causes changes in the electrical properties of the sensitive cell, which in turn modulates the oscillation frequency. This vibration-based approach enables measurement without requiring continuous external power during irradiation.
2Adaptability or versatility
If radiation sensor operates without power supply, then application versatility is improved, but measurement accuracy may deteriorate
Solution Approach 1:
The patent incorporates a feedback mechanism where the oscillating circuit continuously monitors the electrical properties of the radiation-sensitive cell and adjusts its operation accordingly. The counter integrates the oscillation signals over time, providing cumulative measurement that compensates for variations in instantaneous signal strength, thereby maintaining measurement accuracy during unpowered operation.
Solution Approach 2:
The system performs preliminary calibration and setup during powered operation, storing reference values in memory. During subsequent unpowered radiation measurement phases, these pre-stored references are used to interpret the measurement signals, ensuring accuracy is maintained even without active power supply during the critical measurement period.
3Measurement precision
If continuous radiation monitoring is enabled, then radiation exposure tracking is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple functions into a single integrated circuit device. The radiation-sensitive cell, oscillating circuit, counter, and memory are merged into one compact unit. This integration achieves continuous radiation monitoring capability while minimizing overall device complexity through functional consolidation rather than separate discrete components.
Solution Approach 2:
The oscillating circuit serves multiple functions: it generates the measurement signal, acts as a frequency modulator responsive to radiation, and provides a timing reference for the counter. This multi-functionality reduces the need for separate dedicated components, thereby achieving continuous monitoring without proportionally increasing device complexity.
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
Enables continuous radiation monitoring and recording regardless of power status, ensuring accurate exposure tracking and enabling actions based on radiation levels, such as sterilization confirmation in medical or food safety contexts.
Implementation Method 1
The resistance of the radiation-sensitive cell is configured to vary in response to incident radiation
Data Source
AI summary
This disclosure is directed to devices, integrated circuits, and methods for sensing radiation. In one example, a device includes an oscillator, configured to deliver a signal via an output at intervals defined by an oscillation frequency, and a counter, connected to the output of the oscillator and configured to count a number of times the comparator delivers the output signal. The oscillator includes a radiation-sensitive cell that applies a resistance. The resistance of the radiation-sensitive cell is configured to vary in response to incident radiation, wherein the oscillation frequency varies based at least in part on the resistance of the radiation-sensitive cell.