Smart material

About: Smart material is a research topic. Over the lifetime, 3704 publications have been published within this topic receiving 74280 citations. The topic is also known as: intelligent material & responsive material.

Carbon Dots: An Emerging Smart Material for Analytical Applications.

Abstract: Carbon dots (CDs) are optically active carbon-based nanomaterials. These nanomaterials can change their light emission properties in response to various external stimuli such as pH, temperature, pressure, and light. The CD's remarkable stimuli-responsive smart material properties have recently stimulated massive research interest for their exploitation to develop various sensor platforms. Herein, an effort has been made to review the major advances made on CDs, focusing mainly on its smart material attributes and linked applications. Since the CD's material properties are largely linked to their synthesis approaches, various synthesis methods, including surface passivation and functionalization of CDs and the mechanisms reported so far in their photophysical properties, are also delineated in this review. Finally, the challenges of using CDs and the scope for their further improvement as an optical signal transducer to expand their application horizon for developing analytical platforms have been discussed.

Multiscale Design of Flexible Metal–Organic Frameworks

Abstract: Flexible materials can adapt to external stimuli with predictable and controllable responses. The emergence of dynamic behavior in metal–organic frameworks (MOFs) is promising for the development of ‘smart’ materials for applications that leverage their porosities and tunable chemical compositions, including the storage, separation, and sensing of small molecules. The translation of molecular structural transformations to macroscopic responses requires the multiscale design of flexible MOF systems. This review summarizes the progress in this area focusing on the past 3–5 years, starting from the modular assembly of building blocks and continuing to the management of dynamics in device architectures.

Non-linear response of dipolar colloidal gels to external fields

Abstract: Dipolar colloids can be made to gel by forming a reversible but persistent network of chain-like aggregates at very low volume fractions. Using the model of charged soft dumbbells in molecular dynamics simulations, we find that, under the effect of an external electric field, this gel displays a highly non-linear dielectrical susceptibility. We show that the latter is caused by a switch from a network to a structure of bundling chains when the field is strong enough. Such dramatic structural transformation upon applying external fields could allow to control the mechanical and dielectric response of these complex fluids, pointing to new applications of dipolar colloids as smart materials.

An optimized cross-linked network model to simulate the linear elastic material response of a smart polymer

Abstract: This article presents a novel approach to model the mechanical response of smart polymeric materials. A cyclobutane-based mechanophore, named “smart particle” in this article, is embedded in an epoxy polymer matrix to form the self-sensing smart material. A spring–bead model is developed based on the results from molecular dynamics simulation at the nanoscale to represent bond clusters of a smart polymer. The spring–bead network model is developed through parametric studies and mechanical equivalence optimization to represent the microstructure of the material. A statistical network model is introduced, which is capable of bridging the high-accuracy molecular dynamics model at the nanoscale and the computationally efficient finite element model at the macroscale. A comparison between experimental and simulation results shows that the multiscale model can capture global mechanical response and local material properties.

Electroosmotically driven microfluidic actuators

Abstract: A prototype electroactive polymer actuator has been developed based on electroosmotic (EO) pumping to create hydraulic pressure. The actuator was fabricated from poly(dimethylsiloxane) (PDMS) with embedded micro-scale channels, reservoirs, and electrodes surmounted by a membrane. An applied voltage caused one reservoir to expand as fluid was pumped into it, and the other reservoir to contract, with the membrane above the expansion reservoir rising by 400 μm within a few seconds. Since the prototype was made from PDMS, which is an elastomer, the device was entirely flexible. The actuator performance was characterized, and it agreed well with predicted values. Furthermore, the calculations indicate that, once optimized, such actuators could have high stress as well as high strain and high speed. By combining unit cells such as these into a material and actuating them individually via independently controlled flexible electrodes, one could realize smart materials that could change shape. Other future applications may include micro-valves, micro-positioners, soft robots, and active camouflage layers.