HIGH-THROUGHPUT BIOMECHANICAL TISSUE STRETCHING DEVICE
September 2018 - May 2019
Final Device
A key design constraint was that the final device had to be easily manipulated on a standard inverted microscope stage. This image is a proof of concept.
Image A shows the initial design concept, featuring a single well plate and two small linear actuators. In order to ensure equal strain on all wells, we realized the pull had to be from the middle, resulting in dual well plates and a single linear actuator, as seen in Image B. Image C was optimized for manufacturability and refined for use with the inverted microscope.
Key Design Iterations
Final Device
Image A depicts the device in the unstretched, loading position. Image B depicts the device in the fully stretched position, 9mm above the surface.
Exploded View
Labeled, exploded view of the device SolidWorks 3D assembly.
Calibration Image Analysis
Image A depicts the well prior to stretch, while Image B depict the well mid-stretch. The % stretch was calculated based on the displacement of the dots using at MATLAB algorithm. In future applications, the wells will be coated in a hydrogel with embedded fluorescent microbeads, developed by researchers at Harvard Medical School. The program will be further developed to calculated the stress and strain that the tissue samples experience.
Indenter Rapid Prototyping
Several iterations of the indenters were designed and 3D printed to best determine the optimal sizing, placement, and mounting of the ball bearings. The ball bearings are vital to the device as they reduce friction in order to not damage tissue samples during testing.