Piezoresistive Pressure Sensor Breakwater Gel Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pressure sensors used in harsh environments, such as motor vehicles, experience lead wire failure due to mechanical stresses and vibration-induced wave fronts, which cause fatigue and sudden fracture of the bond between lead wires and the substrate, leading to connection failure.
Innovation Solution
Incorporating breakwater structures within the sensor cavity to reduce and redirect vibration-induced pressure waves, minimizing the force exerted on lead wires and preventing fatigue or sudden fracture by creating destructive interference and altering the wave direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If gel is used to protect electronic devices from corrosive chemicals, then chemical protection is improved, but vibration-induced wave fronts cause lead wire failure
Solution Approach 1:
A foam material is introduced as an intermediary substance between the gel and the lead wires. The foam serves as a buffer that absorbs vibration-induced wave fronts while allowing the gel to maintain its chemical protection function. This intermediary layer prevents direct transmission of mechanical stresses to the lead wires and their bonds.
Solution Approach 2:
The invention converts the harmful vibration-induced wave fronts into beneficial damping effects by allowing controlled vibration of the foam material. The foam's cellular structure dissipates vibration energy through internal friction and cell wall deformation, transforming harmful mechanical energy into harmless thermal energy.
2Volume of moving object
If lead wires are made thin to reduce space, then device compactness is improved, but mechanical strength and resistance to vibration stresses deteriorate
Solution Approach 1:
The foam material provides beforehand cushioning to the thin lead wires by absorbing vibration-induced wave fronts before they can reach the wires. This protective layer is positioned in advance within the cavity, allowing the thin lead wires to maintain their compact design while being protected from mechanical stresses that would otherwise cause fatigue and failure.
3Quantity of substance
If gel fills the entire cavity for maximum protection, then chemical coverage is improved, but vibration wave transmission to lead wires increases
Solution Approach 1:
The cavity is segmented into different functional zones: a gel-filled zone for chemical protection and a foam-containing zone for vibration damping. This segmentation allows the gel to provide maximum chemical coverage while the foam intercepts vibration-induced wave fronts, preventing them from reaching the lead wires with full force.
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 implementation of breakwater structures effectively reduces the amplitude and impact force of vibration-induced waves, thereby enhancing the reliability and longevity of lead wire connections within the pressure sensor.
Implementation Method 1
minimizing the force exerted on lead wires and preventing fatigue or sudden fracture by creating destructive interference and altering the wave direction
Data Source
AI summary
A piezoresistive pressure sensor that uses a protective gel to protect the piezoresistive device is susceptible to lead wire failure by vibration-induced waves in the protective gel. Such waves can be reduced and the device made more robust by the use of three-dimensional structures in the gel, which are configured to reduce and/or re-direct vibration-induced pressure waves in the gel. The structures are referred to as “breakwaters” in that they protect lead wires and lead wire connections from wave fronts and the damage that wave-induced pressure on the lead wires causes.