Acoustic Sensor Backing Structure with Non-Uniform Protrusions

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Acoustic impedance sensors face challenges in efficiently directing acoustic energy towards the forward direction due to energy being drawn away in other directions without an air gap and backing layer, leading to reduced output amplitude.

Innovation Solution

Incorporating an air gap and a backing layer with a lower acoustic impedance than the forward medium, and using a non-uniform distribution of protrusions on the backing layer to minimize contact area and enhance acoustic energy reflection, thereby increasing forward transmission of acoustic energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If no air gap and backing layer are used, then the device structure is simpler, but acoustic energy is drawn away in directions other than forward, reducing output amplitude

Engineering Contradiction:

Improvestructure complexityVSAvoidacoustic energy loss

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

An air gap is introduced as an intermediary layer between the sensor and the backing layer. This air gap acts as an acoustic impedance matcher that reduces the reflection of acoustic energy at the sensor-backing interface, thereby minimizing energy loss in the rearward direction while maintaining structural simplicity

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The backing layer is designed with lower acoustic impedance than the forward medium (finger tissue). By changing the acoustic impedance parameter of the backing layer material, the system optimizes acoustic energy transmission in the forward direction while reducing energy reflection and loss

Inventive Principle:

Principle #35Parameter changes

2Ease of manufacture

If a uniform backing layer is used, then the manufacturing process is simpler, but acoustic energy reflection is not optimized, reducing forward transmission efficiency

Engineering Contradiction:

Improvebacking layer fabricationVSAvoidacoustic energy transmission efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The backing layer is designed with a non-uniform distribution of protrusions rather than a uniform structure. This local variation in the backing layer geometry creates zones of different acoustic impedance, optimizing acoustic energy reflection and forward transmission efficiency while maintaining reasonable manufacturing feasibility through molding or machining processes

Inventive Principle:

Principle #3Local quality

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 air gap and backing layer design increases upward acoustic energy transmission by 30% and reduces energy loss in the rearward direction, improving the sensor's efficiency in sensing biometric characteristics.

Implementation Method 1

backing layer with a lower acoustic impedance than the forward medium... enhance acoustic energy reflection... increases upward acoustic energy transmission by 30%

Methodology Applied

Scientific EffectAcoustic impedance: Acoustics

Data Source

PatentUS9841318B1Apparatus for acoustic sensing

Publication Date: 2017.12.12 SONAVATION TECHNOLOGIES LLC

AI summary

The invention provides an improved acoustic energy generating apparatus that includes an improved backing structure. The improved backing structure employs protrusions that are not located in a uniform pattern along a forward side surface of the backing structure, to realize improved re-direction of acoustic energy towards a forward direction relative to the acoustic energy generating apparatus.