Piezoelectric Actuator with Self-Powered Liquid Crystal Display

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Solution Overview

Problem

Existing actuating devices with indicator lights rely on external energy sources, making them non-autonomous and requiring permanent power supplies, such as batteries, which limits their self-sufficiency.

Innovation Solution

An actuating device with a piezoelectric blade-based voltage generator that produces electrical voltages through deformations, powering a liquid crystal display with two stable states, allowing for autonomous operation without external power, using a multilayer structure of piezoelectric material, insulator, and conductive metal layers, and a rotary rack system for controlling displacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional indicator lights (lamps, LEDs) are used, then the device can display control states, but it requires external power sources (power grid or batteries) reducing autonomy

Engineering Contradiction:
ImproveautonomyVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The piezoelectric blade generates electrical energy from the mechanical deformation caused by the movable part's displacement. The system serves itself by converting its own operational mechanical energy into electrical energy to power the display, eliminating the need for external power sources and achieving complete autonomy

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The piezoelectric material's electrical output parameters (voltage amplitude) change in response to the amplitude of mechanical deformation. By varying the displacement distance of the movable part, different voltage amplitudes are generated, enabling the display to show different control states based on the physical state of the system

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If complex processing circuits are used with LEDs, then the device can provide signaling commands, but the device complexity increases and external energy sources are required

Engineering Contradiction:
Improvesignaling capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the complex processing circuits from the system by using a liquid crystal display that can be directly controlled by the piezoelectric-generated voltage. The signaling capability is maintained through the display's ability to show different states, while the complexity is reduced by removing unnecessary electronic components

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the electrical/mechanical processing circuit system with a direct electromechanical coupling where the piezoelectric blade's mechanical deformation directly generates the electrical signal that controls the liquid crystal display, simplifying the overall system architecture

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If batteries are used for power supply, then the device can operate independently, but the device requires permanent local energy sources reducing self-sufficiency

Engineering Contradiction:
ImproveindependenceVSAvoidenergy storage material
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of carrying energy storage materials like batteries, the system generates its own energy on-demand from the mechanical deformation during operation. The piezoelectric blade converts the kinetic energy of the movable part's displacement into electrical energy, allowing the device to be independent without requiring permanent local energy sources

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system recovers mechanical energy from the movable part's displacement that would otherwise be wasted, converting it into electrical energy to power the display. This energy recovery approach eliminates the need for separate energy storage materials while maintaining operational independence

Inventive Principle:
Principle #34Discarding and recovering

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

Enables autonomous operation of the actuating device with a liquid crystal display that maintains its state after each command, using deformations to generate voltages for indicating control states without the need for continuous power, enhancing self-sufficiency and reducing energy dependency.

Implementation Method 1

at least one electrical voltage generator element (7) arranged between the mobile part (2) and a stop (8) of the fixed part (1), said generator element being capable of receiving at least two stresses or deformations according to the two displacement distances

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The indicator (3) comprises or consists of a display with two stable states, for example, a liquid crystal display having two different colors corresponding to each stable state

Methodology Applied
Scientific EffectLiquid crystal effect: Liquid Crystals

Data Source

PatentEP2461224B1Actuator device with pilot lamp and push button comprising such a device
Publication Date: 2014.06.04 SCHNEIDER ELECTRIC IND SAS
  • EP2461224B1 patent drawingFigure 1~2
  • EP2461224B1 patent drawingFigure 3~4C
  • EP2461224B1 patent drawingFigure 5~6C

AI summary

The indicator light actuator comprises a fixed part (1) serving as the housing, a movable part (2) capable of moving between a rest position and at least one active position, and an indicator light (3) for displaying a state. A system (4) for controlling the displacement of the movable part (2) relative to the fixed part (1) sequentially controls at least two different displacement distances (D1, D2) between two consecutive actions. At least one electrical voltage-generating element (7) is disposed between the movable part (2) and the fixed part (1). The element can receive at least two stresses or deformations dependent on the two displacement distances (D1, D2) to provide voltages of different amplitudes (V1, V2). The indicator light (3) is connected to said voltage-generating element (7) and includes a display with two stable states. The push button includes the actuator.