Sputtered Thin Film Strain Gauge Cross-Beam Sensor

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Solution Overview

Problem

Current multi-dimensional force sensors using strain gauges face issues with low temperature range stability and performance degradation due to glue volatilization and condensation, limiting their effectiveness in harsh environments.

Innovation Solution

A six-dimensional force sensor elastomer structure based on an improved cross-beam design that incorporates thin film strain gauges sputtered onto main and floating beams, reducing inter-dimensional coupling and internal stress errors, and allowing for precise force and moment measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional strain gauges with glue are used, then the sensor can be manufactured with current technology, but the temperature range is limited and performance degrades due to glue volatilization and condensation

Engineering Contradiction:

Improvetemperature rangeVSAvoidperformance stability

Core Design Contradiction:

TemperatureVSReliability

Solution Approach 1:

The patent removes the glue layer from the strain gauge assembly process. By directly bonding the strain gauge to the diaphragm without adhesive, it eliminates the source of volatilization and condensation problems, enabling the sensor to operate in extreme temperature ranges from -196℃ to 200℃ without performance degradation

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the bonding method parameter from adhesive-based to direct bonding. This parameter change eliminates the chemical composition issues associated with glue, allowing the sensor to maintain reliability across extreme temperature ranges that would otherwise cause glue volatilization and condensation

Inventive Principle:

Principle #35Parameter changes

2Reliability

If thin film strain gauges are sputtered, then glue-related issues are eliminated and temperature resistance improves, but the manufacturing process becomes more complex

Engineering Contradiction:

Improveheat and humidity resistanceVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the mechanical adhesive bonding process with a sputtering deposition process. This substitution eliminates glue-related reliability issues and enables heat and humidity resistance, though it requires vacuum deposition equipment and process control

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent uses thin film composite structures where the strain gauge is deposited as a thin film layer directly on the diaphragm surface. This composite approach integrates the sensing element and substrate, eliminating the need for separate adhesive layers and improving environmental resistance

Inventive Principle:

Principle #40Composite materials

3Device complexity

If a conventional cross-beam structure is used, then the sensor structure is simple, but inter-dimensional coupling and internal stress errors increase

Engineering Contradiction:

Improvestructure simplicityVSAvoidforce measurement accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent segments the cross-beam structure by adding floating beams that are not rigidly connected to the main beams. This segmentation allows independent deformation of different beam segments, reducing inter-dimensional coupling effects and improving measurement precision for six-dimensional force sensing

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic flexibility to the cross-beam structure through floating beams with degrees of freedom. The floating beams can deform independently in response to applied forces, enabling the structure to dynamically adapt to multi-dimensional loading conditions while reducing coupling errors

Inventive Principle:

Principle #15Dynamics

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 solution enhances sensor stability, sensitivity, and accuracy by eliminating glue-related issues, improving heat and humidity resistance, and reducing assembly errors, making it suitable for aerospace applications.

Implementation Method 1

A sputtering process does not necessitate the use of glue, so it is of great practical significance to sputter thin film strain gauges through the sputtering process

Methodology Applied

Scientific EffectSputtering: Sputtering

Implementation Method 2

A resistance strain-type multi-dimensional force sensor based on a cross-beam structure is currently the most widely used sensor, which converts deformation of the sensor under stress into a voltage change through strain gauges

Methodology Applied

Scientific EffectStrain gauge resistance change: Piezoresistive Effect

Data Source

PatentUS20240328876A1Sputtering thin film six-dimensional force sensor elastomer structure based on improved cross beam

Publication Date: 2024.10.03 SOUTHEAST UNIV

AI summary

A six-dimensional force sensor elastomer structure based on improved cross beam includes main beams, first floating beams, second floating beams, square corners and thin film strain gauges. Strain gauges are sputtered on the main beams and the first floating beams to form a plurality of sets of Wheatstone bridges. When an input force/moment of a certain dimension acts on the center of an elastomer, the sensor is deformed and resistance values of strain gauges at corresponding positions change, so that output voltages of corresponding bridges are changed.