Water-Repellent DLC Microtome Blade for Chipping Resistance
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Solution Overview
Problem
Existing microtome blades suffer from insufficient water repellency, leading to specimen sticking and chipping, especially when cutting thin specimens, and require improved durability and cutting performance across varying specimen hardness.
Innovation Solution
A microtome blade with a water-repellent DLC thin film having a contact angle of 90 degrees or more, radius of curvature between 15 nm and 250 nm, and film thickness between 15 nm and 150 nm, combined with a wedge angle of 15 to 50 degrees, made of cemented carbide or stainless steel, to enhance cutting performance and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a hard carbon film is formed on the blade surface to improve durability, then cutting durability is improved, but water repellency is insufficient causing specimen sticking
Solution Approach 1:
The blade combines a hard carbon film layer with a water-repellent coating layer to create a composite surface structure. The hard carbon film provides durability and wear resistance, while the water-repellent coating layer (containing fluorine and/or silicon) provides hydrophobicity with contact angles of 90 degrees or more. This composite structure resolves the contradiction by integrating two functional layers that simultaneously provide both durability and water repellency.
Solution Approach 2:
The invention changes the chemical composition parameters of the coating by incorporating fluorine and/or silicon elements into the carbon film structure. This compositional modification transforms the surface properties to achieve both high hardness/durability and high water repellency, resolving the contradiction between durability and water repellency through parameter optimization.
2Ease of operation
If a microtome blade with small wedge angle is used for soft specimens, then cutting performance for soft specimens is improved, but chipping occurs when cutting hard specimens
Solution Approach 1:
The invention optimizes the wedge angle parameter to a specific range (15 to 50 degrees) that balances cutting performance for soft specimens with resistance to chipping for hard specimens. This parameter optimization allows the blade to maintain excellent cutting performance on soft specimens while the strengthened cutting edge (through the water-repellent DLC thin film) prevents chipping when cutting hard specimens, resolving the contradiction through parameter tuning.
3Object-affected harmful factors
If a microtome blade with large wedge angle is used for hard specimens, then chipping is prevented, but cutting performance for soft specimens deteriorates
Solution Approach 1:
The invention optimizes the wedge angle parameter to a specific range (15 to 50 degrees) that balances cutting performance for soft specimens with resistance to chipping for hard specimens. This parameter optimization allows the blade to maintain excellent cutting performance on soft specimens while the strengthened cutting edge (through the water-repellent DLC thin film) prevents chipping when cutting hard specimens, resolving the contradiction through parameter tuning.
4Ease of operation
If different wedge angles are used for different specimen types, then cutting performance for each specimen type is optimized, but device complexity increases
Solution Approach 1:
The invention creates a universal blade design that can effectively cut both soft and hard specimens using a single blade type with wedge angle of 15 to 50 degrees. The water-repellent DLC thin film coating enables this single blade to perform optimally across different specimen types, eliminating the need for multiple specialized blades and thereby reducing device complexity while maintaining cutting performance optimization.
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 blade effectively prevents specimen sticking and chipping, maintaining cutting quality and extending lifespan regardless of specimen hardness, suitable for both soft and hard tissues.
Implementation Method 1
water repellency is imparted to the cutting edge. However, it cannot be said that the durable cutting blade of Patent Literature 1 exhibits sufficient water repellency at the cutting edge
Data Source
Figure 1(A)~1(B)
Figure 2~3
Figure 4~5
AI summary
To provide a blade for microtomes, the blade suppressing chipping, exhibiting excellent cutting performance and durability, and achieving favorable cutting, irrespective of hardness of a specimen to be cut out. A blade for microtomes, the blade including: a blade body including a base portion and a sharpened portion 1B, the base portion having a flat plate shape, the sharpened portion 1B being formed at a tip of the base portion; and a water-repellent DLC thin film 2 formed on the sharpened portion 1B, wherein a contact angle of water on the water-repellent DLC thin film 2 is 90 degrees or more, a radius of curvature (R1) of a distal end E of the sharpened portion 1B is 15 nm or more and 150 nm or less, a radius of curvature (R2) of a distal end F of a cutting edge including the water-repellent DLC thin film 2 is 30 nm or more and 250 nm or less, and is larger than the radius of curvature (R1) of the distal end E of the sharpened portion 1B, and a film thickness (d) of the water-repellent DLC thin film 2 is 15 nm or more and 150 nm or less.