https://phys.org/ en-us Latest news from Inha University Magnetically responsive microtextured surfaces have the advantage of being controlled remotely (i.e., no contact is required) at ambient conditions and short response times. Previously, synchronized bending or twisting actuations of micropillar arrays were demonstrated by programming the arrangement of the magnetic particles and by employing anisotropic micropillar geometry. In this case, magnetic particles are included in a polymer matrix at low concentrations to avoid magnetic interference and thereby achieve synchronized actuation. Researchers from Inha University (Jeong Eun Park and Jeong Jae (JJ) Wie), Air Force Research Laboratory (Augustine Urbas and Zahyun Ku), and Lawrence Livermore National Laboratory (Sei Jin Park) recently reported an opposite strategy to induce magnetic self-assembly of micropillar arrays. Highly concentrated magnetic micropillars act as micromagnets and collectively assemble with neighboring pillars under an applied magnetic field. For facile actuation, flexible rubber is utilized for pillar-base while relatively rigid and magnetically responsive pillar-tops undergo the magnetic assembly. As the pillar-base is magnetically inert and fixed to substrate, self-assembly of periodically arranged micropillars can repeat reversible and reproducible assembly and recovery by modulating the external magnetic field. https://phys.org/news/2022-02-stepwise-magnetic-self-assembly-micropillar-arrays.html Nanomaterials Tue, 01 Feb 2022 09:18:41 EST news562929519 A triboelectric nanogenerator (TENG) is an energy-harvesting device that converts mechanical energy into electricity through contact separation or relative sliding movements of two opposite tribo-polar materials. Researchers from Inha University previously reported the first example of sulfur backbone polymer-based TENG. The surface of the sulfur copolymer film was directly fluorinated using toxic fluorine gas to enhance TENG performance. https://phys.org/news/2021-11-triboelectric-nanogenerators-polymeric-sulfur-blends.html Nanophysics Tue, 23 Nov 2021 11:04:25 EST news556887862 Azobenzene-functionalized liquid crystalline materials can be operated by remote light-stimuli without complicated circuits or parts and thus are attracting great attention in fields such as human interfaces, haptic devices, and miniaturized soft robots. https://techxplore.com/news/2021-10-light-fueled-torsional-soft-robot-rapidly.html Robotics Mon, 25 Oct 2021 08:58:14 EDT news554371089 Azobenzene functionalized liquid crystalline polymers are considered "smart" materials owing to their programmable shape transformations under various external stimuli (i.e., thermal, chemical, and photomechanical shape morphing). In particular, their light responsivity allows for untethered powering and actuating systems. Now, researchers from Inha University have demonstrated preparation and actuation of reduced graphene oxide patterned azo-LCN (azo-LCN/rGO) with highly enhanced elastic modulus, electrical conductivity, and photomechanical actuation performance. https://phys.org/news/2021-05-3d-reconfiguration-stretchable-electronics.html Materials Science Fri, 28 May 2021 07:06:05 EDT news541404363 Jumping movement is commonly observed in nature, including for mammals, insects and the other land creatures; this fluid motion aims for rapid mobility, a faster arrival time at a destination over large obstacles and rough terrain. The qualitative properties of the jump such as direction and height are regulated by mere fractions of potential and kinetic energy. In addition, an organism can opt to repeat its jumping motions as decided by its own free will. https://phys.org/news/2021-05-molecular-enables-photomechanical-polymers.html Materials Science Fri, 21 May 2021 13:32:00 EDT news540822717 Triboelectric generation is an energy harvesting technique that generates electricity through induction of triboelectric effects using discarded physical energy. Materials employed to triboelectric generators (TEG) are classified positive or negative according to their value of electron affinity; negative materials generally employ fluorinated carbon-based polymers. Yet, most of the research for improving TEG performance focus mainly on structural improvements of device such as the multi-layer device structures, testing triboelectricity in a vacuum condition, and asymmetric device design rather than the development of novel polymeric materials. https://phys.org/news/2019-12-high-performance-triboelectric-materials-fabricated-by-products.html Nanophysics Wed, 04 Dec 2019 10:08:47 EST news494676526 Magnetic soft robots are a promising option for contactless control in confined environments via external magnetic stimuli. Magneto-induced motions, i.e., magnetomotility, are driven by local deformation of a robot whereby particle alignments and alternating polar distributions are programmed into the body. Attempts to program magnetic anisotropy into the soft robots have been performed through direct laser printing (DLP), stereolithography (SLA) and fused filament fabrication (FDM) combined with multi-axial manipulation of electromagnets. https://techxplore.com/news/2019-11-multiple-helical-magnetic-soft-robots.html Robotics Wed, 20 Nov 2019 07:46:30 EST news493458382