2022, Vol. 26 ›› Issue (21): 3306-3311

Design of an automatic measurement system for the micro-mechanical properties of three-dimensional printing biomaterials

Feng Chen1, 2, Zhou Jiping3, Xu Xiaodong1, 2, Jiang Yani3, Shi Hongcan4, Zhao Guoqi1   

Abstract: BACKGROUND: In the existing evaluation system of tissue engineering scaffolds, it is usually necessary to test the mechanical strength of scaffolds in many aspects to ensure that they can meet the requirements of clinical application. However, because the measurement of mechanical properties of biological composite materials is a small deformation measurement, it is difficult to have professional measuring instruments on the market to meet the accuracy requirements. The commonly used hardness tester or tensile tester is difficult to meet the requirements of the mechanical properties of the scaffold.  
OBJECTIVE: To develop a device with the function of automatic detection of hardness and toughness to detect the mechanical properties of the biological scaffold.
METHODS: This test system used two sets of differential bridges to realize the output of stress and strain respectively, and mechanical tests were conducted in different ways under constant temperature, humidity and strain rate to obtain various mechanical properties of the material. Aiming at the particularity of composite biomaterials, the equipment testing of biocomposite materials composed of nanocellulose and polycaprolactone was conducted to verify whether this test system can meet the requirements.
RESULTS AND CONCLUSION: Through experiments, the test system could accurately reflect the mechanical properties of biomaterial scaffolds. Taking the slope of the “force displacement” loading curve of the tested scaffolds as the characterization of the toughness/hardness of the scaffolds, the mechanical properties of the scaffolds could be visualized, and the accuracy of the test system could reach 0.1 μm. It has theoretical basis and application value for the establishment of three-dimensional bioprinting in tissue damage repair.
Key words: three-dimensional printing biomaterial, slight deformation, differential bridge, automatic detection, biological composite materials, mechanical property, test system