Humidity-responsive polymeric actuators have gained considerable interest due to their great potential in the fields including soft robotics, artificial muscles, smart sensors, and actuators. However, most of them can only exhibit invariable shape changes, which severely restricts their further exploration and practical use. Herein, we report that programmable humidity-responsive actuating behaviors can be realized by introducing photoprogrammable hygroscopic patterns into shape memory polymers. Poly(ethylene--acrylic acid) is selected as a model polymer and the solvent-processed thin films are soft and elastic, whose external shapes can be programmed by a modified shape memory process. On another aspect, an Fe-carboxylate coordinating network formed by surface treatments can be spatially dissociated under UV, resulting in transient hygroscopic gradients as active joints for moisture-driven actuation. Moreover, we show that the shape memory effect can be an effective means to adjust the direction as well as the amplitude of the moisture-driven actuating behavior. The proposed strategy is convenient and can be generally extended to other shape memory polymers to realize programmable moisture-responsive actuating behaviors.
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http://dx.doi.org/10.1021/acsami.1c24018 | DOI Listing |
Behav Processes
January 2025
Surrey Sleep Research Centre, University of Surrey.
Visuospatial working memory (VSWM) is crucial for navigating complex environments and is known to decline with ageing. The Free-Movement Pattern (FMP) Y-maze, used in animal studies, provides a robust paradigm for assessing VSWM via analyses of individual differences in repeated alternating sequences of left (L) and right (R) responses (LRLR, etc.), the predominant search pattern in many species.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, 150001, P. R. China.
Electric-field-induced shape memory effect has potential applications in electromechanical actuator. Here, this study proposes the a phase structure design routine in (1-x)(75NaBiTiO-25SrTiO)-xPbTiO ceramics to obtain large electromechanical response and shape memory effect. It is found that the shape memory effect is closely related to the bending deformation induced by asymmetric polarization between positive and negative electrodes, which is resulted from the reductions of Bi and Pb because of electron injection from negative electrode.
View Article and Find Full Text PDFLangmuir
January 2025
Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States.
We demonstrate, using non-equilibrium molecular dynamics simulations, that lipid membrane capacitance varies with surface charge accumulation linked to membrane shape and curvature changes. Specifically, we show that lipid membranes exhibit a hysteretic response when exposed to oscillatory electric fields. The electromechanical coupling in these membranes leads to hysteretic buckling, in which the membrane can spontaneously buckle in one of two distinct directions along the electric field, even for the same ionic charge accumulation at the water-membrane interface.
View Article and Find Full Text PDFBiomater Sci
January 2025
Department of Nanobiomedical Science & BK21 FOUR micropatterned shape-memory NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan 31116, Republic of Korea.
A scaffold design for tendon regeneration has been proposed, which mimics the microstructural features of tendons and provides appropriate mechanical properties. We synthesized a temperature-triggered shape-memory polymer (SMP) using the ring-opening polymerization of polycaprolactone (PCL) with polyethylene glycol (PEG) as a macroinitiator. We fabricated a micropatterned patch using SMP capillary force lithography, which mimicked a native tendon, for providing physical cues and guiding effects.
View Article and Find Full Text PDFNutr Health
January 2025
Department of Audiology, All India Institute of Speech and Hearing, Mysore, India.
A nutritious diet is crucial for good health and cognitive function, including working memory (WM). Nutrients like omega-3 fatty acids, antioxidants, and vitamins found in whole foods have been linked to improved WM. Examining the impact of dietary habits on WM in women, who face hormonal and health-related challenges, is important.
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