Wireless Open-Circuit Strain Sensor Eliminates Solder Connections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional electrical strain sensors require electrical connections, which lead to reliability issues, increased costs, and environmental concerns due to solder use, and pose challenges in maintenance and recycling.
Innovation Solution
A wireless in-plane strain and displacement sensor with an electrically unconnected conductor pattern that resonates in a time-varying magnetic field, generating harmonic electric and magnetic responses, eliminating the need for solder connections and physical attachments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrical connections and solder are used to connect circuit elements, then the circuit can function reliably, but the device cost increases, manufacturing complexity increases, and environmental hazards arise
Solution Approach 1:
The patent extracts and eliminates the electrical connection components (solder, wires, circuit boards) from the sensor system. The sensor uses a resonant circuit formed by conductive traces on a flexible substrate that can be wirelessly excited and read, removing the need for traditional electrical connections while maintaining sensor functionality.
Solution Approach 2:
The patent replaces the mechanical/electrical connection system with a wireless electromagnetic field-based system. The sensor is excited by a time-varying magnetic field and its response is read wirelessly, substituting physical electrical connections with electromagnetic field interactions.
2Ease of manufacture
If solder is used to connect circuit elements, then electrical connections are established, but manufacturing cost increases and toxic venting systems are required
Solution Approach 1:
The patent removes solder and traditional circuit board fabrication processes from the manufacturing system. The sensor is fabricated using conductive traces deposited on a flexible substrate, eliminating the need for soldering operations and associated toxic fume generation.
3Ease of manufacture
If high heat is applied to melt solder, then electrical connections are formed, but circuit boards may be stressed or damaged
Solution Approach 1:
The patent extracts the high-temperature soldering process from the manufacturing sequence. The conductive traces are formed using low-temperature deposition techniques on the flexible substrate, avoiding the high heat application that would stress or damage the circuit board.
4Measurement precision
If traditional electrical strain sensors are used, then strain measurement is achieved, but the sensors require closed electrical circuits that increase device complexity and reduce recyclability
Solution Approach 1:
The patent replaces the closed electrical circuit requirement with a wireless electromagnetic resonance system. The sensor contains an open-circuit resonant structure that is excited by a time-varying magnetic field, eliminating the need for closed electrical circuits while maintaining strain measurement capability through changes in resonant frequency or impedance.
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 reduces manufacturing costs, enhances reliability, and allows for recyclability, enabling wireless operation and reduced environmental impact, while providing continuous monitoring of strain and displacement without the need for electrical connections.
Implementation Method 1
In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses
Implementation Method 2
In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses
Implementation Method 3
The first and second ends remain electrically unconnected such that the electrical conductor so-shaped defines an unconnected open-circuit having inductance and capacitance
Implementation Method 4
The first and second ends remain electrically unconnected such that the electrical conductor so-shaped defines an unconnected open-circuit having inductance and capacitance
Data Source
AI summary
A wireless in-plane strain and displacement sensor includes an electrical conductor fixedly coupled to a substrate subject to strain conditions. The electrical conductor is shaped between its ends for storage of an electric field and a magnetic field, and remains electrically unconnected to define an unconnected open-circuit having inductance and capacitance. In the presence of a time-varying magnetic field, the electrical conductor so-shaped resonates to generate harmonic electric and magnetic field responses. The sensor also includes at least one electrically unconnected electrode having an end and a free portion extending from the end thereof. The end of each electrode is fixedly coupled to the substrate and the free portion thereof remains unencumbered and spaced apart from a portion of the electrical conductor so-shaped. More specifically, at least some of the free portion is disposed at a location lying within the magnetic field response generated by the electrical conductor. A motion guidance structure is slidingly engaged with each electrode's free portion in order to maintain each free portion parallel to the electrical conductor so-shaped.