High-Throughput Rheometer Using Decaying Oscillation

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Solution Overview

Problem

Rheometers require extended measurement times for large amplitude oscillatory shear (LAOS) tests, which limits throughput and can cause material degradation, such as heating, dehydration, or mechanical breakdown.

Innovation Solution

A rheometer that measures the transient response of materials during decaying oscillation, allowing for the extraction of broadband dynamic property data from a single oscillation cycle, reducing measurement time and minimizing material degradation, using a fixture, mass, actuator, and position sensor to induce and monitor free vibration, and processing signals with the Hilbert transform to isolate frequency components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If large amplitude oscillatory shear (LAOS) measurements are performed by cycling through many different amplitudes and frequencies, then detailed characterization of material dynamic qualities is achieved, but measurement time is extended and material degradation is accelerated

Engineering Contradiction:

Improvedetailed characterization of material dynamic qualitiesVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies mechanical vibration by inducing free oscillation in the material sample through an actuator that imparts initial velocity to a mass attached to the material. The material naturally oscillates at its resonant frequency, and this vibration is monitored by a position sensor to extract dynamic properties. This approach replaces the traditional method of cycling through multiple amplitudes and frequencies with a single free oscillation measurement, dramatically reducing measurement time while maintaining characterization accuracy.

Inventive Principle:

Principle #18Mechanical vibration

2Measurement precision

If large amplitude oscillatory shear (LAOS) measurements are performed by cycling through many different amplitudes and frequencies, then detailed characterization of material dynamic qualities is achieved, but material degradation is accelerated through heating, dehydration, or mechanical breakdown

Engineering Contradiction:

Improvedetailed characterization of material dynamic qualitiesVSAvoidmaterial degradation

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses free oscillation at the material's natural frequency rather than forced oscillation at multiple frequencies. This single-frequency approach reduces cumulative mechanical stress and heating on the material, preventing degradation while still providing comprehensive dynamic characterization through analysis of the oscillation decay and frequency content.

Inventive Principle:

Principle #18Mechanical vibration

3Measurement precision

If traditional LAOS protocol is used to characterize materials, then broadband dynamic property data is obtained, but throughput is limited due to extended measurement times

Engineering Contradiction:

Improvebroadband dynamic property dataVSAvoidmeasurement throughput

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent measures the material's natural frequency and damping characteristics through free oscillation, then uses Hilbert transform to extract broadband dynamic properties from this single oscillation signal. This method obtains the same comprehensive data that would require cycling through multiple frequencies in traditional LAOS, but in a single measurement, thereby dramatically increasing throughput.

Inventive Principle:

Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces the mechanical cycling system (actuator cycling through multiple amplitude-frequency combinations) with a signal processing system (Hilbert transform algorithm). Instead of mechanically varying the excitation parameters, the system uses mathematical transformation to extract broadband information from a single oscillation measurement, substituting mechanical complexity with computational analysis.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach significantly shortens measurement time, increases throughput, and allows for accurate characterization of materials by extracting data from multiple frequencies and amplitudes in a single cycle, while providing independent measurements of damping and modulus, and enabling material identification and damping evaluation.

Implementation Method 1

an actuator used for inducing an initial velocity to the mass at an actuation time and allowing the mass and material to oscillate in decaying free vibration after the actuation time

Methodology Applied

Scientific EffectFree vibration: Vibration

Implementation Method 2

oscillate in decaying free vibration

Methodology Applied

Scientific EffectDamping: Damping

Implementation Method 3

A position sensor monitors the position of the mass after the actuation time in a dimension of oscillation to provide a set of electronic signals indicating position as a function of time

Methodology Applied

Scientific EffectPosition sensing:

Implementation Method 4

This data may be processed, for example, using the Hilbert transform to isolate from a single oscillation decay, slowly-varying frequency components

Methodology Applied

Scientific EffectHilbert transform:

Data Source

PatentUS10996156B2High-throughput rheometer

Publication Date: 2021.05.04 WISCONSIN ALUMNI RES FOUND

AI summary

A high throughput rheology machine measures transient response to a material subject to the decaying oscillation to determine nonlinear characteristics of the material with a single test cycle.