Piezoelectric Actuator Haptic Feedback Bandwidth Voltage Trade-off

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional haptic feedback technologies in electronic devices, such as touch screens, face limitations in bandwidth and require high voltages, making them unsuitable for providing high definition haptic feedback, especially with the advancement of high definition display screens.

Innovation Solution

The use of a piezoelectric actuator with an elongated piezo bender and a flexible holder, driven by an electrical signal generator, to create vibrations and provide haptic feedback, allowing for control of frequency and amplitude to enhance user experience.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional haptic feedback technologies (LRA, ERM, EAP devices) are used, then haptic feedback can be provided, but bandwidth is limited or high voltage is required

Engineering Contradiction:

ImprovebandwidthVSAvoidvoltage requirement

Core Design Contradiction:

Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces conventional mechanical haptic actuators (LRA, ERM) and high-voltage EAP devices with a piezoelectric actuator system. The piezoelectric material converts electrical signals directly into mechanical vibrations through the piezoelectric effect, enabling high-bandwidth haptic feedback with low voltage requirements, thus resolving the contradiction between bandwidth and voltage requirement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters by using piezoelectric materials that operate at room temperature with low voltage, unlike conventional actuators that require high voltage or have limited bandwidth. The piezoelectric actuator can be driven at high frequencies with low voltage, achieving both high bandwidth and low voltage operation simultaneously.

Inventive Principle:

Principle #35Parameter changes

2Manufacturing precision

If display screen definition is increased, then visual feedback quality improves, but haptic feedback definition lags behind

Engineering Contradiction:

Improvedisplay definitionVSAvoidhaptic feedback definition

Core Design Contradiction:

Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The patent segments the haptic feedback system into multiple independent piezoelectric actuators that can be individually controlled. Each actuator can be driven at different frequencies and amplitudes, allowing high-definition haptic feedback that matches the resolution of high-definition display screens. The flexible holder allows precise positioning and control of each actuator segment.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses dynamic control of piezoelectric actuators with adjustable frequency and amplitude through the flexible holder mechanism. This dynamic capability enables the system to adapt haptic feedback characteristics to match the temporal and spatial resolution of high-definition displays, providing synchronized multi-sensory feedback.

Inventive Principle:

Principle #15Dynamics

3Volume of moving object

If actuator size is reduced for compact devices, then device portability improves, but haptic feedback performance may degrade

Engineering Contradiction:

Improvedevice sizeVSAvoidhaptic feedback performance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent employs piezoelectric composite materials that combine high piezoelectric coefficient with mechanical compliance. This allows the actuator to generate strong haptic feedback forces in a compact form factor. The flexible holder structure complements the composite material by providing mechanical compliance that enhances vibration transmission while maintaining a compact overall device size.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent uses a flexible holder structure that allows the piezoelectric actuator to be mounted in a compact configuration. The flexible holder transmits vibrations effectively while accommodating the small size of the piezoelectric element, enabling high-performance haptic feedback in compact devices without sacrificing reliability.

Inventive Principle:

Principle #30Flexible shells and thin films

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 solution enables the delivery of high definition haptic feedback with reduced voltage requirements and improved compatibility with high definition displays, enhancing user interaction and sensory experience in electronic devices.

Implementation Method 1

a piezoelectric actuator including an elongated piezo bender

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9152264B2Electronic device with piezoelectric actuator

Publication Date: 2015.10.06 TDK ELECTRONICS AG

AI summary

An electronic device includes a touch screen configured to receive an input from a user, and a haptic device that includes a piezoelectric actuator including an elongated piezo bender having a mass at one end thereof and supported by a flexible holder at the other end thereof, and an electrical driving signal generator configured to generate a signal to create a vibration in the elongated piezo bender in response to the input from the user.