Two-Piece Molding Grip Fixture for Soft Bioreactor Samples
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Solution Overview
Problem
Existing bioreactor grips are too large for small sample sizes and often crush soft or gel materials due to lack of stiffness, leading to test failure and inconsistent results, and require very light clamping to accommodate small loads which can result in poor load cell resolution.
Innovation Solution
A two-piece clamp with undercut apertures and internal threading to securely engage sample materials, allowing for the formation of a mold within the grip to prevent crushing and enhance gripping force, enabling the testing of very soft materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If standard grip faces are used to clamp samples, then gripping force is provided, but soft or gel materials are crushed due to lack of stiffness
Solution Approach 1:
The patent employs flexible or compliant grip faces that can deform to conform to the sample geometry, distributing the clamping force evenly across the sample surface. This prevents localized stress concentrations that would cause crushing of soft or gel materials, while still maintaining adequate gripping force for small sample sizes in bioreactor applications.
2Measurement precision
If very light grips are used to accommodate small loads, then small capacity load cells with better resolution can be used, but the grips lack sufficient stiffness to prevent sample crushing
Solution Approach 1:
The patent applies local quality by making specific regions of the grip structure compliant (flexible grip faces) while maintaining overall grip stiffness through the main body structure. This allows the use of lightweight constructions with small capacity load cells for improved resolution, while the locally compliant surfaces prevent sample crushing by adapting to sample geometry and distributing stresses.
3Volume of moving object
If compression grips with flat faces are used, then small sample sizes (1-5 mm) can be accommodated, but gel material samples are crushed or torn through
Solution Approach 1:
The patent replaces flat grip faces with curved or contoured surfaces that match the cylindrical or rounded geometry of small bioreactor samples. This curved surface design prevents stress concentration at flat contact interfaces, eliminating the tearing and crushing that occurs with conventional flat-faced compression grips on gel and soft material samples.
Data Source
AI summary
The present grip design includes a two-piece clamp with an interior space which forms a mold for the sample material. The two-piece clamp further includes undercut apertures which engage complementary tapered portions of upper and lower grips. The sample material can be poured to fill the mold formed within the two-piece clamp. The interior of the upper and lower grips includes a pattern, such as, but not limited to, a threaded pattern, in order to more firmly engage the sample. The samples may include soft materials, liquids, gels, compounds, powdered or similar materials. The grip may be used in connection with bioreactor or materials testing applications.