Biomaterials Testing

One of the things we do routinely in the Fudge Lab is to measure the mechanical properties of biomaterials to test hypotheses about how they function in life. This involves the use of custom-designed mechanical testing devices as well as two commercial systems built by Instron and MTS.

Instron 3343 Benchtop Universal Testing Machine

This system allows us to conduct mechanical tests on biomaterials in compression or tension. Specialized immersible grips and a sample bath allow us to test materials either in air or immersed in fluid. Bluehill software allows us to design custom mechanical testing regimes.
Instron UTM with submersible BioPuls pneumatic grips

MTS Nano Bionix Tensile Tester

This system allows us to measure the mechanical properties of fibres with diameters less than a micron. The kinds of fibres that can be tested on this system include silks produced by insects and spiders, as well as the protein fibres found in hagfish slime.

MTS Nano Bionix Tensile Testing System

Cell Biophysics

Our interest in elastic biomaterials extends to materials within cells, such as intermediate filaments. These 10 nm diameter filaments reinforce keratinized structures such as hair, nail, horn, and whale baleen, but they are also present within most living cells in most animals. To probe the mechanical behavior of intermediate filaments in living cells, we grow cells on deformable rubber substrates and stretch them under a microscope using a custom-built cell stretching device. Expresssion of fluorescently-tagged intermediate filament proteins in these cells allows us to monitor the behavior of these proteins as cells are deformed using epipfluorescence.

Stretched IF Networks

Microscopy

We make use of a variety of microscopy techniques to study the biomechanics of cells, tissue, and organisms. Our Nikon Eclipse 90i epifluorescent microscope allows us to carry out experiments using fluorescent probes such as GFP. This system includes a sensitive monochrome camera for capturing faint fluorescent signals, as well as a fast color camera for capturing biological events at shorter timescales. We also use transmission electron microscopy and scanning electron microscopy to test hypotheses about biomaterial structure at the nanoscale.

Nikon_Eclipse 90i