Passive Wireless Sensor for Droplet Detection via Resonant Frequency Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current droplet and bubble detection methods are inadequate due to susceptibility to noise, vibration, environmental factors, and the need for external power sources, leading to inaccuracies and limitations in size, generation speed, flow rate, and quantity measurement, as well as instability in fluid systems affecting biological cell capture and culture.
Innovation Solution
A passive wireless sensor utilizing a microfluidic chip with inductor channels forming a resonant circuit, where changes in permittivity between the channels result in changes in resonant frequency, allowing for non-contact detection of droplets and bubbles without external power, reducing device size and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic detection method is used, then droplet or bubble detection can be achieved, but the detection is susceptible to noise and vibration interference
Solution Approach 1:
The patent replaces acoustic detection with a wireless resonant circuit detection system that uses electromagnetic fields instead of mechanical acoustic waves. The resonant circuit formed by inductor channels and capacitor channels detects droplets and bubbles through changes in permittivity, eliminating susceptibility to noise and vibration interference while maintaining detection capability.
2Measurement precision
If optical detection method is used, then droplet or bubble detection can be achieved, but the detection is susceptible to temperature and oil permeability variations
Solution Approach 1:
The patent substitutes optical detection with a resonant circuit-based detection method that measures changes in permittivity. This approach is independent of optical properties and is not affected by temperature or oil permeability variations, thereby eliminating environmental factor sensitivity while preserving detection accuracy.
3Measurement precision
If inductance or capacitance detection method is used, then droplet or bubble detection can be achieved, but external power source and wire connections are required
Solution Approach 1:
The patent implements a self-powered resonant circuit where the inductor channels and capacitor channels form a closed loop that generates its own oscillations. The circuit detects droplets and bubbles through changes in resonant frequency caused by permittivity variations, eliminating the need for external power sources and wire connections while maintaining detection capability.
4Measurement precision
If traditional detection methods are used, then droplet or bubble detection can be achieved, but device size is larger and service life is shorter
Solution Approach 1:
The patent merges the detection function with the fluid flow path by integrating inductor channels and capacitor channels into the microfluidic chip structure. The resonant circuit is formed within the chip itself, eliminating the need for separate external components and reducing overall device size while maintaining detection functionality.
Solution Approach 2:
The self-powered resonant circuit eliminates the need for external power sources and complex wiring, reducing device size and improving reliability. The circuit operates autonomously by detecting changes in its own resonant frequency, thereby extending service life and reducing maintenance requirements.
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 accurate, loss-free, and repeatable detection of droplets and bubbles, expanding application possibilities and prolonging device lifespan by eliminating external interference and power source requirements.
Implementation Method 1
the first inductor channel and the second inductor channel together form a resonant circuit; when a detection object passes through the detection channel, the permittivity between the first inductor channel and the second inductor channel changes. Consequently, the capacitance value of the capacitor channel changes, thus resulting in a change in resonant frequency of the resonant circuit
Implementation Method 2
when a detection object passes through the detection channel, the permittivity between the first inductor channel and the second inductor channel changes
Data Source
AI summary
Disclosed a passive wireless sensor for detecting discrete droplets and bubbles. A first inductor channel and a second inductor channel are disposed opposite each other to form a capacitor channel, the first inductor channel is connected to the second inductor channel to form a resonant circuit. When a detection object passes through the detection channel, the permittivity between the first inductor channel and the second inductor channel changes and consequently a capacitance value of the capacitor channel changes, thus resulting in a change in resonant frequency of the resonant circuit. A readout device is used to read the resonant frequency of the resonant circuit and perform detection according to the resonant frequency to obtain information of a corresponding detection object.