Smart Polymers for Advanced Applications: A Mechanical Perspective Review

Abstract

Responsive materials, as well as active structural systems, are today widely used to develop unprecedented smart devices, sensors, or actuators; their functionalities come from the ability to respond to environmental stimuli with a detectable reaction. Depending on the responsive material under study, the triggering stimuli can have a different nature, ranging from physical (temperature, light, electric or magnetic field, mechanical stress, etc.), chemical (pH, ligands, etc.), or biological (enzymes, etc.) type. Such a responsiveness can be obtained by properly designing the meso-or macroscopic arrangement of the constitutive elements, as occurs in metamaterials, or can be obtained by using responsive materials per se, whose responsiveness comes from the chemistry underlying their microstructure. In fact, when the responsiveness at the molecular level is properly organized, the nanoscale response can be collectively detected at the macroscale, leading to a responsive material. In the present article, we review the enormous world of responsive polymers, by outlining the main features, characteristics, and responsive mechanisms of smart polymers and by providing a mechanical modeling perspective, both at the molecular as well as at the continuum scale level. We aim at providing a comprehensive overview of the main features and modeling aspects of the most diffused smart polymers. The quantitative mechanical description of active materials plays a key role in their development and use, enabling the design of advanced devices as well as to engineer the materials' microstructure according to the desired functionality.

Integration of Machine Learning and Coarse-Grained Molecular Simulations for Polymer Materials: Physical Understandings and Molecular Design

“…Due to the limitations of current experimental techniques, molecular dynamic (MD) simulations have provided an effective alternative approach to characterize the structures and molecular mechanisms of polymers. In MD simulations, the equations of motion are used to derive the positions and velocities of atoms and molecules via external and interatomic forces ( Brighenti et al, 2020 ). By doing so, we are able to explore the molecular structures and thermodynamic properties of polymers.…”

Multiphysics modelling of the mechanical properties in polymers obtained via photo-induced polymerization

“…sinθdθdβ, with θ, β being the Euler angles of the end-to-end vector r in the 3D space [30,39]. The mechanical response of the polymer is assumed to take place after the completion of the photopolymerization process, i.e., the micromechanical model enters into play only after printing the material.…”

Shaping Macromolecules for Sensing Applications—From Polymer Hydrogels to Foldamers

“…Polymers are versatile materials that represent a broad range of properties and stimuli-responsiveness, thus very attractive for sensors construction [ 12 , 13 , 14 , 15 , 16 ]. These materials can be adapted to specific tasks through their synthesis or modification [ 17 , 18 , 19 ] and may be used as solid membranes, gels, nanoparticles, or thin films [ 20 , 21 , 22 , 23 ].…”