Nonlinear Mass Sensors Using Electronic Feedback
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Solution Overview
Problem
Existing microscale resonant sensor designs for mass, stiffness, and chemical/biological sensing rely on linear phenomena, which are costly, complex, and not suitable for portable applications, and bifurcation-based sensing methods require high drive amplitudes that can damage devices.
Innovation Solution
A nonlinear electronic feedback approach using quartz tuning fork resonators to produce tunable bifurcations, allowing for collocated actuation and sensing with reduced costs and improved reliability, employing analog feedback loops with operational amplifiers and multipliers to achieve Duffing-like frequency responses at lower excitation amplitudes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linear sensing methods are used with high sensitivity requirements, then measurement precision is improved, but device complexity and cost increase due to requiring phase-locked loops and lock-in amplifiers
Solution Approach 1:
The patent implements electronic feedback loops that sense the resonator's motion and apply corrective forces to maintain constant amplitude oscillation. This feedback mechanism eliminates the need for external phase-locked loops and lock-in amplifiers, achieving high sensitivity measurements while reducing system complexity and cost
Solution Approach 2:
The resonator system performs its own measurement and control functions through integrated feedback electronics. The system self-regulates its oscillation amplitude and frequency without requiring external sophisticated measurement equipment, making the device self-sufficient and reducing overall system complexity
2Measurement precision
If bifurcation-based sensing is used to achieve high sensitivity, then measurement precision is improved, but reliability deteriorates because high drive amplitudes (18 V peak-to-peak) can damage the device
Solution Approach 1:
Electronic feedback loops continuously monitor the resonator's oscillation amplitude and adjust the drive signal in real-time to maintain constant amplitude. This prevents the resonator from being subjected to damaging high drive amplitudes while still enabling bifurcation-based high sensitivity measurements
Solution Approach 2:
The system dynamically adjusts its operating parameters through feedback control, transitioning from static high-amplitude drive to dynamic amplitude regulation. This allows the system to operate in the nonlinear bifurcation regime for high sensitivity while maintaining amplitude levels that protect the device from damage
3Measurement precision
If bifurcation-based sensing is implemented, then measurement precision is improved, but use of energy increases due to requirement for higher power circuitry to function
Solution Approach 1:
The feedback control system efficiently manages energy by only providing the minimum necessary drive amplitude to maintain constant oscillation. This eliminates the need for continuously high-power circuitry while still achieving the nonlinear effects needed for high sensitivity measurements
Solution Approach 2:
The system changes its operating parameters dynamically through feedback control, adjusting drive amplitude and frequency to optimize energy efficiency. This allows operation in the nonlinear regime for high sensitivity while minimizing power consumption compared to continuous high-power operation
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 solution enables sensitive, tunable, and robust mass, chemical, and biological sensing with reduced costs, eliminating the need for customized designs and allowing for lower power consumption, making it suitable for portable applications.
Implementation Method 1
quartz tuning fork resonators to produce tunable bifurcations
Implementation Method 2
quartz tuning fork resonators
Implementation Method 3
nonlinear electronic feedback approach using quartz tuning fork resonators to produce tunable bifurcations, allowing for collocated actuation and sensing with reduced costs and improved reliability, employing analog feedback loops with operational amplifiers and multipliers to achieve Duffing-like frequency responses
Data Source
AI summary
A device and method for sensing including a sensor having a functional surface layer located to interact with a material to be sensed, the sensor having an output that produces a signal responsive one or more of inertia, stiffness, acceleration, pressure, radiation, chemical compounds, and biological compounds; and further including electronics including: an input coupled to the sensor to receive a first signal therefrom; and a non-linearity provider that applies one or more non-linear operations to the input signal to generate a non-linear second signal.