Magnetic Sample Handling for Cryogenic X-ray Analysis
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Solution Overview
Problem
Existing sample handling systems for cryogenically cooled samples in X-ray structure analysis face issues with mechanical failure due to severe temperature changes and heat transfer, leading to sample damage and increased nitrogen evaporation.
Innovation Solution
A system comprising a sample storage with a permanent magnet and an electromagnetic coil for a magnetic or magnetizable sample holder, where the control unit adjusts the current through the coil to change the gripping force, minimizing heat deposition and eliminating the need for electrical components in the cold environment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If mechanical gripping devices are used to transfer samples from cryogenic storage to measuring device, then sample transfer can be automated, but the devices are prone to mechanical failure due to severe temperature changes and heat transfer
Solution Approach 1:
The patent replaces mechanical gripping devices with a magnetic field-based gripping system. Electromagnetic coils generate magnetic fields that interact with magnetizable sample holders, eliminating mechanical contact and the associated reliability issues from temperature-induced warping and icing. The magnetic field provides contactless gripping that is not affected by thermal expansion or material brittleness at cryogenic temperatures.
Solution Approach 2:
The system changes the physical state and properties of the gripping mechanism by using electromagnetic fields instead of mechanical forces. The electromagnetic coils can dynamically adjust the magnetic field strength to control gripping force, providing reliable operation across temperature transitions without the mechanical failure modes of conventional grippers.
2Strength
If conventional materials like stainless steel are used in gripping devices, then structural strength is maintained, but heat transfer into the Dewar increases causing undesirable nitrogen evaporation
Solution Approach 1:
By replacing mechanical gripping structures with electromagnetic coils, the patent eliminates the need for thermally conductive structural materials that would transfer heat to the cryogenic environment. The electromagnetic actuation mechanism requires minimal thermal mass and can be designed with thermally isolating materials, significantly reducing heat leak into the Dewar and nitrogen evaporation.
3Ease of operation
If electrical components are placed in the cold space inside the Dewar, then control of the gripping device is enabled, but heat transfer through electrical ducts increases and special materials are required
Solution Approach 1:
The patent extracts the electrical control components from the cryogenic environment. The electromagnetic coils are positioned outside the Dewar, with only the magnetic field penetrating into the cold space to interact with the sample holders. This eliminates the need for thermal insulation of electrical ducts and associated heat transfer losses, while still enabling full control of the gripping function.
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 system reduces mechanical failures and heat transfer, allowing for reliable and efficient handling of samples while maintaining cryogenic conditions, minimizing heat input into the cooling liquid, and enabling flexible design and operation.
Implementation Method 1
the first sample position comprises a first permanent magnet, which is configured to apply a holding force on the first sample holder
Implementation Method 2
the gripping apparatus comprises a sample gripper having an electromagnetic gripping device comprising an electromagnetic coil, the electromagnetic gripping device being configured to apply a gripping force on the first sample holder
Implementation Method 3
the electromagnetic coil is configured to enhance or attenuate a magnetic flux of the permanent magnet, and the control unit is configured in that it can control the current through the electromagnetic coil so as to enhance or attenuate the gripping force applied on the sample holder by the permanent magnet
Data Source
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AI summary
The invention relates to a system 1 for handling of a sample 35, comprising a sample storage 7 having a first sample position 15*, a first magnetic or magnetizable sample holder 3, a control unit 9 and a gripping apparatus 11. The sample storage 7 is configured for use in a cold environment and the first sample position 15* is configured to receive the first sample holder 3 which is configured to hold the sample 35. The first sample position 15* comprises a first permanent magnet 25, which is configured to apply a holding force on the first sample holder 3. The gripping apparatus 11 comprises a sample gripper 23 having an electromagnetic gripping device 47 comprising an electromagnetic coil 41 being configured to apply a gripping force on the first sample holder 3. The control unit 9 is coupled to the electromagnetic coil 41 in that it can control a current through the electromagnetic coil 41 so as to change the gripping force applied on the first sample holder 3. The control unit 9 is configured to control the current through the electromagnetic coil 41 in an holding mode in that the gripping force generated by the electromagnetic gripping device 47 is set to a holding value such that the first sample holder 3 can be lifted from the first sample position 15* and/or to control the current through the electromagnetic coil 41 in a release mode in that the gripping force generated by the electromagnetic gripping device 47 is set to a release value such that the first sample holder 3 cannot be lifted from the first sample position 15* by the sample gripper 23.