Composites of functional polymers: Toward physical intelligence using flexible and soft materials

Abstract

Materials that can assist with perception and responsivity of an engineered machine are said to promote physical intelligence. Physical intelligence may be important for flexible and soft materials that will be used in applications like soft robotics, wearable computers, and healthcare. These applications require stimuli responsivity, sensing, and actuation that allow a machine to perceive and react to its environment. The development of materials that exhibit some form of physical intelligence has relied on functional polymers and composites that contain these polymers. This review will focus on composites of functional polymers that display physical intelligence by assisting with perception, responsivity, or by off-loading computation. Composites of liquid crystal elastomers, shape-memory polymers, hydrogels, self-healing materials, and transient materials and their functionalities are examined with a viewpoint that considers physical intelligence. Graphic Abstract

Liquid Metal Microdroplet‐Initiated Ultra‐Fast Polymerization of a Stimuli‐Responsive Hydrogel Composite

“…Recent trends in the development of hydrogels offer a wide range of material characteristics (e.g., high mechanical stretchability, [1] high electrical [2,3] and thermal conductivity [4] ), multifunctionalities (e.g., actuation, [5][6][7] batteries, [8][9][10] energy harvesting, [11] and self-healing [12,13] ), programmability [14] and physical intelligence. [15][16][17] Composite hydrogels, with fillers ranging from microscale (e.g., liquid metal microdroplets [13] and graphene oxide [18] ) to nano-scale (e.g., carbon nanotubes [19] and silver nanowires [20] ), provide the hydrogel matrices with electrical or mechanical reinforcement into their material properties beyond their intrinsic limits. In addition to material enhancement, functional fillers can also bring their specialized capabilities to the hydrogel.…”