Material Testing of Miniature Samples: Solving a Biomedical Problem
The biomedical industry continues to drive innovations in biomaterials, but much of that innovation requires measuring the mechanical properties of miniature samples. Therein lies the problem. Few materials testing systems are able to measure low capacity and small displacement movements on samples that can often be difficult to hold. Furthermore, many researchers have a need to record microscopic material behavior while the sample is subjected to forces—a need that requires small-sized testing systems that can fit on microscope stages. This is the market opportunity that ADMET identified for their line of eXpert 4000 series Microtesters. In this article, three examples that demonstrate how the Microtester was deployed in the market are featured. These are great applications that prove the need for small scale testing solutions.
The Cancer Story
The ongoing development of cancer research is exploring many new avenues to help cure or mitigate its various forms. A research group at a large national organization wanted to explore stiffness profiles of biopsies taken from normal and malignant tissue. The goal was to gain a greater understanding of how the progression of cancer affects the extracellular matrix. This large organization approached ADMET because they were unable to find a solution that met their needs. Based on their requirements, ADMET supplied a portable eXpert 4000 MicroTester that was capable of quickly and accurately obtaining a force deflection curve for stiffness studies. A wheeled, hard carrying case was supplied with the MicroTester, which allowed the researches to easily transport it from location to location.
The Stent Manufacturer Problem
One of the big four stent manufacturers was exploring methods to test their stents to a higher quality standard. The company was already performing the basic tension/compression, radial force, and three-point bend tests; however, they were looking to dive deeper into the mechanical performance of their device. The problem that was presented to ADMET was they could not find a reliable solution capable of measuring the strength of individual welds. The company had been attempting the measurements for some time, but was unable to get repeatable results due to problems clamping the stent around a weld. ADMET delivered an eXpert 4000 MicroTest 45N solution with custom clamps and digital microscope. The clamps included locating pins so that the weld could be quickly isolated and clamped uniformly. The digital microscope was integrated with ADMET’s MTESTQuattro Materials Testing System so that they could obtain images during test to verify that each weld was properly tested. The resulting solution increased their testing throughput by 10× and provided repeatable results.
The University Research Story
A professor at a prestigious university in the Northeast was focusing his research on soft biological tissues’ viscoelasticity properties (time dependent response to loading). This professor approached ADMET looking for a solution that was capable of simulating real-life movement of tendons and tissues within the body. While testing mice tendons, it was critical the system could perform 10-micron cyclic testing within a heated saline bath. The professor was also interested in positioning the testing apparatus on his inverted microscope to view the specimen’s reactions to movements and proteins. ADMET delivered an engineered eXpert 4000 MicroTester solution specifically for this professor’s microscope stage. The MicroTester, equipped with ADMET’s MTESTQuattro controller, allowed him to evaluate changes in soft tissue viscoelastic properties, while simulating processes including exercise, aging, injury, and disease.
As research and products develop, there will be many more needs for small scale material testing and these three applications are just some of the many applications in the biomedical industry today.