Hydrogels as dynamic memory with forgetting ability

Significance Life provides the best demonstration of complex and adaptive nonequilibrium system, which executes biological functions through nonequilibrium structure transformation. Creating lifelike materials to achieve part of or full biological functions is a grand challenge. Traditional memories from hard and dry materials are static, with no ability of forgetting; here we propose to use soft and wet hydrogels to achieve dynamic memories with spontaneous but learning-strength-dependent forgetting ability by using nonequilibrium structure transformation, in analogy to the human brain. We believe the concept of dynamic memorizing–forgetting behavior proposed here inspires further research on developing lifelike materials based on the nonequilibrium process of soft matter.