AFM Acoustic Analysis Device with Prism-Mounted Piezo Actuators

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current atomic force microscopy devices face limitations in precision and reliability due to manual positioning of ultrasonic excitation sources, piezoelectric actuators causing optical path shifts, and incompatibility with liquid environments, which affects the accuracy and safety of sample analysis, especially for biological samples.

Innovation Solution

An acoustic analysis device using an atomic force microscopy setup with independent piezoelectric actuators mounted on a total reflection prism, allowing for precise control of ultrasonic wave angles and decoupling from the measurement lever, enabling volumetric characterization of samples with improved mechanical stability and signal-to-noise ratio, and allowing operation in liquid environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If piezoelectric actuators are added to the measuring lever to generate ultrasonic waves, then the capability for acoustic analysis is improved, but the optical path shifts causing signal loss and reduced measurement reliability

Engineering Contradiction:
Improveacoustic analysis capabilityVSAvoidmeasurement reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The device separates the ultrasonic wave generation function from the measurement lever. Independent piezoelectric actuators are mounted on the support structure rather than on the lever itself, allowing the lever to remain lightweight and optically stable while still enabling acoustic analysis through external excitation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support structure acts as an intermediary that transmits ultrasonic waves from the piezoelectric actuators to the sample without requiring direct attachment to the measuring lever. This intermediate transmission path allows acoustic excitation while maintaining optical path stability

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If manual positioning of ultrasonic excitation sources is used, then device complexity is reduced, but positioning precision and measurement consistency deteriorate

Engineering Contradiction:
Improvedevice complexityVSAvoidpositioning precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The piezoelectric actuators are pre-positioned at predetermined locations on the support structure that are optimized for generating ultrasonic waves. This preliminary positioning ensures consistent excitation geometry without requiring manual adjustment during operation, maintaining both simplicity and precision

Inventive Principle:
Principle #10Preliminary action

3Reliability

If the piezoelectric actuator path is extended to reach the sample, then ultrasonic wave transmission is improved, but the optical path offset increases causing signal loss

Engineering Contradiction:
Improveultrasonic wave transmissionVSAvoidlaser signal loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The ultrasonic wave generation path is segmented from the optical measurement path. The piezoelectric actuators are positioned on the support structure where they can effectively transmit waves to the sample without interfering with the laser beam path to the photodetector, eliminating the trade-off between wave transmission and optical signal strength

Inventive Principle:
Principle #1Segmentation

4Reliability

If heated adhesive is used to attach the piezoelectric actuator to the sample support, then attachment reliability is improved, but sample heating occurs which can damage biological samples

Engineering Contradiction:
Improveattachment reliabilityVSAvoidsample heating
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention uses cold bonding adhesive instead of heated adhesive, eliminating the need for high-temperature attachment. This approach prioritizes sample integrity over maximum attachment strength, which is acceptable since the support structure provides sufficient mechanical stability for the measurement process

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention converts the potential harm of adhesive attachment by using a cold-bonding method that eliminates thermal damage. The adhesive's sufficient (though not maximum) bonding strength is adequate for the application, transforming a potentially harmful heating process into a safe room-temperature bonding process

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 device achieves non-destructive, nanometric-scale volumetric analysis with enhanced reliability and simplicity, maintaining resolution and performance, and allows for analysis without sample preparation or heating, providing better readability of internal sample elements and compatibility with liquid environments.

Implementation Method 1

at least two independent piezoelectric actuators (11) mounted on mechanical supports (12) and providing ultrasonic waves

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the support comprises a total internal reflection prism, comprising a face on which the sample is placed and at least one opposite face, different from the face on which the sample is placed, against which the piezoelectric actuators are applied, at predetermined positions on said prism to define specific excitation angles of the ultrasonic waves

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 3

comprising a laser diode that emits a beam of light in the direction of the lever and a photodetector that receives said beam of light after reflection on the lever

Methodology Applied
Scientific EffectOptical reflection: Reflection

Data Source

PatentEP3491396B1Device for bulk analysis of an organic or inorganic sample
Publication Date: 2021.09.29 UNIV DE BOURGOGNE (FR)
  • EP3491396B1 patent drawingFigure 1~2
  • EP3491396B1 patent drawingFigure 3~4
  • EP3491396B1 patent drawingFigure 5

AI summary

The invention relates to an acoustic analysis device based on atomic force microscopy for the volume analysis of an organic or inorganic sample (3), comprising a support (4) on which the sample (3) is immobilised, an atomic force microscopy lever (1, 1a) having a free end provided with a part that interacts with an upper face (3a) of the sample (3) and scans said upper face (3a), one or at least two of the independent piezoelectric actuators (11) supplying ultrasonic waves with interferential coupling, and acoustic measurement and analysis bodies associated with the atomic force microscopy lever (1, 1a), characterised in that the support (4) is a total reflection prism (21) to which the piezoelectric actuators (11) are applied, the piezoelectric actuators being applied in determined positions on said prism in order to define determined angles of excitation of the ultrasonic waves.