Electron Microscope Sample Holder for Pulsed Gas Reaction Control
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Solution Overview
Problem
Current methods for observing chemical reactions in transmission electron microscopes face challenges such as slow gas pressure stabilization and insufficient pressure increase near the sample, leading to suboptimal reaction progression and image quality issues due to vibration from gas supply systems.
Innovation Solution
A sample holder with a cylindrical design, incorporating a gas reservoir tank, a high-speed valve, and a gas ejection orifice, which supplies pulsed gas to the sample, allowing rapid pressure control and minimizing vibration through a piezoelectric valve and vibration-proof mechanisms, enabling quick switching of environmental conditions for enhanced reaction observation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If gas is supplied through a long and thin pipe from a gas cylinder, then gas can be delivered to the sample, but the relaxation time for gas pressure to reach steady state becomes very long
Solution Approach 1:
The gas supply system is segmented into multiple components: a gas reservoir tank positioned close to the sample, a high-speed valve for rapid gas release, and a short connecting passage. This segmentation eliminates the need for long thin pipes, enabling rapid pressure stabilization while maintaining adequate gas supply to the sample.
2Productivity
If gas pressure in the vicinity of the sample is increased sufficiently to accelerate chemical reaction, then reaction progression rate improves, but vibration from gas supply system reduces image quality
Solution Approach 1:
A vibration-proof mechanism is introduced as an intermediary between the high-speed valve and the sample holder. This intermediary component isolates the sample holder from vibrations generated during rapid gas supply, enabling high reaction rates without compromising image quality.
3Stress or pressure
If a separating membrane is used to seal gas and sample in an environmental cell, then gas pressure can be increased to atmospheric pressure, but the membrane enters the electron beam path and causes noise
Solution Approach 1:
The separating membrane is extracted from the electron beam path while still maintaining its gas-sealing function. The membrane is positioned in a location that prevents it from interfering with electron beam transmission, eliminating image noise while preserving the ability to maintain high gas pressure for accelerated chemical reactions.
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 enables rapid gas pressure stabilization and increased reaction progression rates, improving image quality and allowing for precise control of chemical reactions, even in high-pressure environments, while reducing vibration and maintaining a stable vacuum in the electron microscope column.
Implementation Method 1
a piezoelectric valve and vibration-proof mechanisms, enabling quick switching of environmental conditions
Implementation Method 2
an orifice for ejecting the gas stored in the gas reservoir tank into the holder outer cylinder
Data Source
AI summary
A sample holder enables easy control of a progress rate of a chemical reaction of a sample to be observed and facilitates observation of the chemical reaction. A sample holder includes a cylindrical holder outer cylinder, a sample holding section that is connected to one end of the holder outer cylinder and holds a sample, a gas reservoir tank that is connected to another end of the holder outer cylinder and stores gas, an orifice for ejecting the gas stored in the gas reservoir tank into the holder outer cylinder, and a valve for controlling a flow of the gas stored in the gas reservoir tank into the orifice. The sample holding section has an open end for discharging the gas supplied from the gas reservoir tank and having passed through the sample.