A device for measuring a mechanical property of a tissue includes a probe configured to perturb the tissue with movement relative to a surface of the tissue, an actuator coupled to the probe to move the probe, a detector configured to measure a response of the tissue to the perturbation, and a controller coupled to the actuator and the detector. The controller drives the actuator using a stochastic sequence and determines the mechanical property of the tissue using the measured response received from the detector. The probe can be coupled to the tissue surface. The device can include a reference surface configured to contact the tissue surface. The probe may include a set of interchangeable heads, the set including a head for lateral movement of the probe and a head for perpendicular movement of the probe. The perturbation can include extension of the tissue with the probe or sliding the probe across the tissue surface and may also include indentation of the tissue with the probe. In some embodiments, the actuator includes a Lorentz force linear actuator. The mechanical property may be determined using non-linear stochastic system identification. The mechanical property may be indicative of, for example, tissue compliance and tissue elasticity. The device can further include a handle for manual application of the probe to the surface of the tissue and may include an accelerometer detecting an orientation of the probe. The device can be used to test skin tissue of an animal, plant tissue, such as fruit and vegetables, or any other biological tissue.

Test fixture grips for testing quasibrittle materials, such as fiber-polymer composites are provided having increased mass and stiffness relative to standard test grips to provide for obtaining postpeak measurements. The design is based on static analysis (using the second law of thermodynamics), confirmed by dynamic analysis of the test setup as an open system. Dynamic analysis of the test setup as a closed system with PID controlled input further indicates that the controllability of postpeak softening under CMOD control is improved not only by increasing the grip stiffness but also by increasing the grip mass.

A method and apparatus for measuring a dynamic tensile stress and/or tensile strain response of a material such as an elastic material and/or a ductile material. The apparatus may include a striker bar, a stretcher bar, and a drive assembly configured to propel the striker bar toward the stretcher bar. The apparatus may further include a stationary specimen mount and a movable specimen mount that receive a test sample. The striker bar and the stretcher bar of the apparatus may provide a continuous stress on the test sample and an accurate tensile stress/strain measurement.

Systems and methods for determining a Material's (MTL) mechanical properties. The methods comprise: coupling a first end of MTL to a First Mechanical Mechanism (FMM) movable in a First Direction (FD) and coupling a second end of MTL to a Second Mechanical Mechanism (SMM) movable in a Second Direction (SD); applying a first Pulling Force (PF) to MTL; applying an Oscillating Force (OF) to MTL; applying a second PF to MTL so as to cause any undulations in MTL to be removed and to cause a loading of fibers or polymeric units that support MTL; allowing MTL to oscillate through a series of cycles of loading and unloading; measuring a strain/stress on MTL as a function of time; determining a natural frequency of MTL based on the strain/stress; and determining an elastic modulus of MTL using the natural frequency.

Test fixture grips for testing quasibrittle materials, such as fiber-polymer composites are provided having increased mass and stiffness relative to standard test grips to provide for obtaining postpeak measurements. The design is based on static analysis (using the second law of thermodynamics), confirmed by dynamic analysis of the test setup as an open system. Dynamic analysis of the test setup as a closed system with PID controlled input further indicates that the controllability of postpeak softening under CMOD control is improved not only by increasing the grip stiffness but also by increasing the grip mass.

According to one embodiment described herein, the forces of a shrink film may be measured. The method of measuring the forces may include providing a shrink film processing unit and a testing vehicle moveable within the shrink film processing unit, positioning a shrink film around the testing vehicle, processing the wrapped testing vehicle by shrinking the shrink film around the testing vehicle as the testing vehicle moves through the shrink film processing unit, and measuring the forces applied by the shrink film on the testing vehicle with one or more force sensors at multiple separate sensor positions on the exterior of the testing vehicle during processing, after processing, or both.

A method for bending test of a flexible screen is disclosed, including: connecting the flexible screen to a fixing device to form two connection ends; and conducting an extrusion test to the flexible screen, including moving the fixing device to change the distance between the connection ends of the fixing device so that the distance is less than or equal to the length of the flexible screen between the two connection ends. A system for bending test of a flexible screen is also disclosed. The above method and system for bending test of a flexible screen, which can simulate an operational environment of the flexible screen by moving the fixing device to conduct an extrusion test to the flexible screen, can reduce testing costs compared with the traditional methods and apparatuses for bending test of a flexible screen.

Embodiments relate to a device for performing a bending test having a base plate, counter bearings connected via the base plate, bearing blocks which in each case comprise a support for applying a bending sample, and a bending punch or a bending rail for exerting a force on a bending sample. The distance of the supports can be set precisely and in a force resistant manner by abutting the counter bearings and the bearing blocks against each other via contact surfaces inclined to the base plate. Further provided is a method for performing a bending test using a device according to the invention, in the case of which a bending sample is applied on the supports and in the case of which a force is exerted between the supports on the bending sample.

A method of evaluating the quality of a thin film layer may include: forming the thin film layer on a substrate; applying a stress to the thin film layer; and evaluating the quality of the thin film layer. A device for evaluating the quality of the thin film layer may include a stress chamber for applying a stress to the thin film layer and a refractive index measuring unit for evaluating the quality of the thin film layer based on a rate of change of a refractive index.

A method and apparatus for measuring a dynamic tensile stress and/or tensile strain response of a material such as an elastic material and/or a ductile material. The apparatus may include a striker bar, a stretcher bar, and a drive assembly configured to propel the striker bar toward the stretcher bar. The apparatus may further include a stationary specimen mount and a movable specimen mount that receive a test sample. The striker bar and the stretcher bar of the apparatus may provide a continuous stress on the test sample and an accurate tensile stress/strain measurement.