Self-Powered Timer Using Fowler-Nordheim Tunneling
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Solution Overview
Problem
Conventional timers require continuous power to track time accurately, which is a limitation for passive devices like credit cards and security badges that generate little to no power, making them unsuitable for long-term time-keeping and secure authentication.
Innovation Solution
A self-powered timer module using a floating-gate transistor with an energy barrier that leaks electrons via Fowler-Nordheim tunneling, coupled with a compensation circuit to maintain continuous time measurement, and integrated into authentication systems for dynamic authentication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional timers are used in passive devices, then time tracking functionality is provided, but the devices cannot operate for extended periods due to insufficient power generation
Solution Approach 1:
The timer module powers itself by harvesting ambient electromagnetic energy through its antenna and rectifying circuitry, eliminating the need for external power sources. This self-powered operation enables passive devices like credit cards and security badges to track time continuously for extended periods without depletion of power reserves
Solution Approach 2:
The system transitions from requiring continuous external power to operating on harvested ambient energy by changing the power source parameter. The rectifier converts electromagnetic energy to electrical energy, and the energy storage element maintains operation during low-energy ambient conditions, enabling long-term time tracking
2Measurement precision
If passive devices generate little to no power, then device simplicity is maintained, but accurate time-keeping for extended periods becomes impossible
Solution Approach 1:
The timer module autonomously harvests and stores ambient electromagnetic energy to power its time-keeping function, ensuring continuous operation with sufficient power to maintain accurate time tracking without requiring external power sources or frequent battery replacement
Solution Approach 2:
The energy storage element pre-charges from ambient energy sources before power is needed, ensuring that sufficient energy is available to maintain accurate time-keeping operations during periods when ambient energy levels may be low or intermittent
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 long-term, accurate time-keeping and secure authentication in passive devices by harnessing ambient energy, overcoming power limitations and enhancing security through synchronized timer outputs.
Implementation Method 1
The energy barrier leaks electrons from an ambient environment of the timer to the floating-gate at a predetermined leakage rate using Fowler-Nordheim (FN) tunneling
Data Source
AI summary
A timer module including a timer and a compensation circuit coupled to the timer is provided. The timer measures time over a first monitoring period. The timer includes a floating-gate and an energy barrier. The floating-gate stores electrons and has an initial state and a measured state. The measured state includes a current time and a current floating-gate voltage. The energy barrier is positioned adjacent the floating-gate and leaks electrons from an ambient environment of the timer to the floating-gate at a predetermined leakage rate using Fowler-Nordheim (FN) tunneling. The compensation circuit selectably adjusts the first monitoring period to facilitate improved robustness of the timer with respect to fabrication mismatch due to the self-compensating dynamics of FN tunneling.