SEM Thin-Film Sample Holder for Live Biological Observation
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Solution Overview
Problem
Existing methods for observing biological samples in a scanning electron microscope, such as those in a hydrated state or with fluid materials, face limitations including exposure to vacuum, damage from electron beam irradiation, and inability to observe three-dimensional structures or movement, due to restrictions in sample preparation and equipment compatibility.
Innovation Solution
A method involving a flexible, insulating, and electron-permeable thin film that follows the sample's surface, sealing it between the film and the sample stage, allowing electron beam irradiation without vacuum exposure, and enabling detection of secondary electrons for precise observation of three-dimensional structure and movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sample is placed in a scanning electron microscope under high vacuum, then electron beam irradiation can be performed for observation, but the sample suffers from water evaporation, vacuum exposure damage, and cannot maintain living state
Solution Approach 1:
A flexible, electron-permeable thin film is introduced to cover the sample, creating a barrier that prevents water evaporation and vacuum exposure while allowing electron beam transmission. This thin film acts as a protective shell that maintains the sample's hydrated environment during observation
Solution Approach 2:
The thin film serves as an intermediary layer between the vacuum environment and the sample, mediating the interaction by blocking harmful vacuum effects and electron beam damage while still permitting necessary electron transmission for imaging
2Stability of the object's composition
If chemical fixation and metal coating are applied to prevent sample damage, then sample stability is improved, but movement and living state are stopped
Solution Approach 1:
The flexible thin film provides mechanical stability and protection without requiring chemical fixation or metal coating, thereby maintaining the sample's natural state and allowing movement to continue during observation
3Object-affected harmful factors
If a thin film is used to seal the sample, then vacuum exposure is prevented, but the film itself may interfere with electron beam transmission and image quality
Solution Approach 1:
A specifically designed thin film with electron-permeable properties is used, balancing the need for vacuum isolation with the requirement for electron beam transmission. The film's thinness and material properties are optimized to minimize interference with electron transmission while maintaining protective function
Solution Approach 2:
The film's physical parameters (thickness, material composition, electron permeability) are carefully controlled and optimized to achieve the desired balance between protection and electron transmission, ensuring high image quality while preventing vacuum exposure
4Measurement precision
If the sample is observed close to the thin film surface, then electron detection is improved, but three-dimensional structure and depth perception are lost
Solution Approach 1:
The observation method is extended to capture information from multiple depths and angles, transforming the limited surface-level detection into comprehensive three-dimensional structural information through multi-dimensional imaging approaches
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 allows for the observation of biological samples in a living state without significant restrictions, providing clear three-dimensional imaging and movement analysis, compatible with existing scanning electron microscopes, while preventing water evaporation and sample damage.
Implementation Method 1
an insulating and electron-permeable thin film... allowing electron beam irradiation without vacuum exposure
Implementation Method 2
preventing water evaporation and sample damage... sealing it between the film and the sample stage
Implementation Method 3
a sample stage supporting a sample; sealing the sample in a gap between the thin film and the sample stage
Data Source
AI summary
Disclosed is a method with which it is possible to observe a biological sample in a living state, without significant restrictions due to the properties of the sample or due to a structural body accommodating the sample. To observe a target sample on a sample stage using a SEM including a radiation source for electron beam irradiation, the method includes:a step of bringing an insulating and electron-permeable thin film into contact with the target sample in such a way as to follow a surface on the radiation source side of the target sample, and sealing the target sample in a gap between the film and the sample stage; anda step of radiating an electron beam onto the target sample from the radiation source through the film.