3D-printed suction clamps for tensile testing of brain tissue

The conventional mounting of ultra-soft biological tissues often involves gluing it between two plates or manually tightening grips. Both methods demand delicate handling skills and are time-consuming. This study outlines the design and practical application of 3D-printed suction clamps for uniaxial tension tests on brain samples. Successful testing was defined by the absence of relevant slippage or the sample being drawn into the clamp. A total of 112 deer brain samples underwent testing using a universal testing machine after one freeze-thaw cycle. These samples were obtained from eight different brain regions. During sample preparation, 7 out of all samples failed. Among the 105 tests, 89 (85%) were successful. Of the 16 unsuccessful tests, 15 samples (14%) slipped, while only one sample (1%) was drawn into the clamp to an extent that testing became impossible. Medulla oblongata samples exhibited exceptionally high slippage at 38%, whereas samples from the temporal cortex, external capsule, and putamen had the lowest slippage in only one single case. In conclusion, suction clamps facilitate high-throughput testing through user-friendly and rapid sample mounting. Testing success is contingent on the specific brain site, with sample slippage being the primary reason for testing failures, while sample inspiration into the clamp is negligible.