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Chemically responsive liquid crystal (LC) based polymers can change their mechanical or optical properties when exposed to chemical triggers. The anisotropy inherent in LC materials allows the programming and control of predictable changes in shape, stiffness, and/or color. By further incorporating ionizable moieties into the polymer formulation, these materials may exhibit a response to chemical stimuli such as pH, solvents, or specific analytes. This mini‐review highlights seminal papers and recent advances in the use of chemoresponsive LC polymers for sensing and actuation. We also discuss how these materials can respond to biochemical stimuli through the immobilization of enzymes into the network, and provide examples of different types of responses (e.g., shape reconfigurations and color transitions). Multiple ways of modulating the response, such as chemical gating and enzyme patterning, are also reviewed. Finally, we illuminate some of the challenges and opportunities in the use of these materials for state‐of‐the‐art applications, including shape‐controllable medical implants and real‐time field‐deployable sensors. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The combination of enzymes and chemically responsive smart materials presents considerable opportunities in anti‐fouling, sensing or medicine. Among stimuli‐responsive polymers, liquid crystal elastomers (LCEs) have emerged as a leading actuator platform due to their inherent programmability, realizing large shape transformations upon exposure to stimuli. Herein, three different hydrolytic enzymes are immobilized into acid‐responsive LCEs, which impart the LCEs with sensitivity to three distinctive classes of biomolecules: lipids, carbohydrates, and peptides. Dye‐doped biocatalytic LCEs readily switch their color and shape upon exposure to the appropriate substrate. Twisted nematic patterning and direct ink writing are used to showcase the versatility of shape changes the enzyme‐containing LCEs may undergo. Multiplexed responsiveness is also demonstrated using a connected array of 3D printed disks, each containing a different enzyme, highlighting the excellent chemical selectivity of the LCEs. This work presents a novel platform of versatile bioresponsive color‐switchable actuators that may have application in a wide range of fields. [ABSTRACT FROM AUTHOR]