Compression fatigue and stress relaxation properties of single network polyacrylamide hydrogels

Double-network hydrogels of different chemical compositions have been developed in recent years for specific load-bearing applications such as tissue engineering, soft robots, and stretchable electronics. The broader commercial applications of these hydrogels have been limited by high manufacturing cost and complex synthesis processes. Single network hydrogels have a potential advantage when compared to the complexity and cost of synthesis processes, although their performance and limitations under different loading conditions have not been investigated thoroughly. This paper presents the limitations of single network polyacrylamide based hydrogel on compression fatigue, stress relaxation and creep properties. Single network polyacrylamide hydrogel was selected as model material due to simple processing and availability. The optimized formulation of hydrogel was used for sample preparation. Better pressure relieving property of hydrogel was observed by stress relaxation and creep properties of the hydrogel. Developed hydrogel displayed good fatigue properties up to 13,000 loading cycle at maximum stress of 520±50 kPa and 200 mm/min crosshead speed