Piezoelectric Inertial Actuator for Wideband Bone Conduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric transcutaneous bone conduction implants struggle to achieve superior performance at both high and low frequencies, with current inertial actuators excelling at higher frequencies but lacking resonance and thus performing poorly at lower frequencies.
Innovation Solution
A piezoelectric inertial actuator design featuring a first layer with a resonance frequency between 400 and 1000 Hz and a second layer with a resonance frequency above 1000 Hz, utilizing PZT 5H or PMN-PT piezoelectric plates and shims, secured to the bone with surgical screws, to enhance low-frequency performance while maintaining high-frequency superiority.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single piezoelectric actuator design is used, then device complexity is reduced, but frequency range performance deteriorates
Solution Approach 1:
The patent merges two actuator mechanisms into a unified multi-layer structure where a first piezoelectric bimorph layer provides high frequency performance and a second inertial actuator layer provides low frequency resonance performance. This integration achieves broad frequency range performance while maintaining relatively simple device architecture.
Solution Approach 2:
The actuator is segmented into distinct functional layers: a first piezoelectric bimorph layer for high frequency operation and a second layer with vibrating mass for low frequency resonance. Each layer is optimized for its specific frequency range, allowing the overall device to cover a broad spectrum while maintaining structural organization.
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 proposed actuator design achieves performance comparable to or exceeding existing bone-anchored hearing aids across a wide frequency range, from 250 to 10000 Hz, by combining inertial and bending forces for effective bone conduction.
Implementation Method 1
a piezoelectric actuator is disclosed, capable of being secured to bone using surgical screws, the actuator having a first layer piezoelectric bimorph
Implementation Method 2
the actuator has a vibrating mass that imparts an inertial force to the underlying skull bone
Data Source
AI summary
Among other things, in general, a piezoelectric actuator for use in a piezoelectric inertial hearing aid is disclosed. The actuator includes at least one bimorph having a top piezoelectric plate, a bottom piezoelectric plate, and a shim with holed ends that extends beyond the length of the plates for securing to bone across, e.g., the mastoid cavity. Actuators having two or morph bimorphs and kits containing the same are also disclosed.