Waveguide Sensor Gap Modulation for Ultrasound Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current optical micro-machined ultrasound sensors (OMUS) lack sufficient sensitivity for detecting external forces, particularly in the context of ultrasound sensing, due to limitations in the design of waveguides and their response to external influences.
Innovation Solution
The sensor employs a waveguide configuration with a first and second waveguide part arranged in close proximity, forming a gap that changes in response to external forces, allowing for high sensitivity in detecting forces. The second waveguide part is positioned on a thin structure, such as a membrane, which can flex or vibrate under external pressure, altering the gap size and affecting the propagation properties of the electro-magnetic wave.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional waveguide design is used, then the device complexity is low, but the measurement precision of external forces is insufficient
Solution Approach 1:
The waveguide is divided into two separate waveguide parts positioned in close proximity to each other, forming a gap. This segmentation allows the waveguide to be integrated with a membrane structure, where the gap size changes in response to external forces, thereby enhancing measurement precision without significantly increasing overall device complexity
Solution Approach 2:
The waveguide parts are arranged in different layers (vertical stacking), with the first waveguide part in a first plane and the second waveguide part in a second plane. This three-dimensional arrangement creates a gap that can be modulated by membrane deformation, enabling force detection through spatial configuration rather than complex material properties
2Measurement precision
If the gap between waveguide parts is made smaller to increase sensitivity, then the measurement precision improves, but the manufacturing precision requirements increase
Solution Approach 1:
The membrane structure serves a dual function: it supports the second waveguide part and simultaneously acts as the sensing element that modulates the gap size in response to external forces. This self-service approach allows the membrane's natural deformation to control the gap, reducing the need for precise external control mechanisms and lowering manufacturing precision requirements for gap control
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
This configuration enhances the sensor's sensitivity to external forces, enabling more accurate detection of ultrasound and other acoustic waves by effectively utilizing the high electro-magnetic field intensity at the gap position, allowing for precise measurement of force-induced changes.
Implementation Method 1
a waveguide for guiding an electro-magnetic wave, wherein the waveguide comprises a first waveguide part and a second waveguide part spaced apart by a gap
Implementation Method 2
The transmitted spectrum at an output port of the waveguide shows dips at optical resonance wavelengths of the ring resonator. Incident acoustical pressure waves strain the membrane and hence the resonator.
Data Source
Figure 1~2
Figure 3~4
Figure 5a~5f
AI summary
A sensor (200) comprises: a thin structure (202), which is configured to receive a force for deforming a shape of the thin structure (202) and which is arranged above a substrate (110); and a waveguide (100) for guiding an electro-magnetic wave comprising: a first waveguide part (102); and a second waveguide part (104); wherein the second waveguide part (104) has a larger width than the first waveguide part (102); and wherein the first and the second waveguide parts (102, 104) are spaced apart by a gap (106) which is sufficiently small such that the first and second waveguide parts (102, 104) unitely form a single waveguide, wherein one of the first and the second waveguide part (102, 104) is arranged at least partly on the thin structure (202) and another of the first and the second waveguide part (102, 104) is arranged on the substrate (110).