Researchers at Tufts University are using Zwick Roell's biaxial testing machine to test biological and engineered biocompatible materials for the development of a soft-bodied robot.
Based on the neuromechanical system of the caterpillar Manduca sexta, the softbot prototype is approximately 30cm long and made of silicone elastomer.
The mechanical material characterisation is performed at the Soft Materials Characterisation Laboratory at Tufts' Advanced Technology Laboratory, led by Professor Luis Dorfmann.
The Zwick Roell biaxial testing machine is being used to characterise isotropic and anisotropic elastomers and help the researchers to model the behaviour of the material.
The machine is equipped with four linear independently controlled actuators of 2kN capacity.
Each actuator is fitted with a loading fixture for applications of tensile or compressive loads to the test sample and a dedicated load cell.
The actuator drive system's travel resolution is 0.1um, while the load cells resolution is 0.001N.
Zwick's Videoxtens extensometer, which is rigidly fixed to the machine frame, allows for non-contact strain measurements of materials that undergo medium to large deformations.
The extensometer is equipped to capture both axial and transverse strains simultaneously in separate input channels.
Camera lenses are interchangeable to permit different field of views and minimum theoretical resolution range from 0.3 um to 6 um.
The testing software Testxpert II installed on a dedicated computer allows universities full customisation of test procedures, loading sequences as well as standard DIN, ISO and ASTM test programs.
To accommodate diverse testing protocols, custom-designed test fixtures can be designed by one of the lab engineers, and coupled with an appropriate force transducer.
A water bath for characterisation of materials in various solutions is also available.
