Tardigrade-inspired extremotolerant glycerogels

We developed extremotolerant glycerogels (GGs) with well-modulated polymer structures, functions, and properties, inspired by the tun formation of tardigrades. GGs comprising extreme protected intra- and intermolecular networks are obtained through a very slow structure building process, which includes the smooth replacement of water in predesigned hydrogels with glycerol and thermal annealing while retaining the structures and functions of the original hydrogels. Four different GGs are fabricated as proofs-of-concept using different crosslinkers and polymers. Although various polyol-based wide-temperature-tolerant gels fabricated by conventional methods fail to demonstrate stabilities at low and high temperature extremes simultaneously, the GGs fabricated by our bioinspired method exhibit long-term stability (approaching one month) over an extremely wide temperature range (-50-80 °C) and thermal-shock-absorption capabilities at 150 °C. Furthermore, our versatile method enables us to program GGs with wide ranges of stiffness, strength, stretchability, and toughness values and elasticity, plasticity, hysteresis, and self-recoverability capabilities. The self-weldability, electrical patternability, and applicability characteristics of the GGs as electrolytes and supercapacitors demonstrate their complex 3D designability and facile functionalization capability aspects. The various functional GGs developed through the proposed method are applicable for the design of diverse extremotolerant, flexible, and stretchable devices for biological, electrical/electronic, and soft robotics applications.