Dynamic functions of biological organisms often rely on arrays of actively deformable microstructures undergoing a nearly unlimited repertoire of predetermined and self-regulated reconfigurations and motions, most of which are difficult or not yet possible to achieve in synthetic systems. Here, we introduce stimuli-responsive microstructures based on liquid-crystalline elastomers (LCEs) that display a broad range of hierarchical, even mechanically unfavored deformation behaviors. By polymerizing molded prepolymer in patterned magnetic fields, we encode any desired uniform mesogen orientation into the resulting LCE microstructures, which is then read out upon heating above the nematic-isotropic transition temperature (T) as a specific prescribed deformation, such as twisting, in- and out-of-plane tilting, stretching, or contraction. By further introducing light-responsive moieties, we demonstrate unique multifunctionality of the LCEs capable of three actuation modes: self-regulated bending toward the light source at T < T, magnetic-field-encoded predetermined deformation at T > T, and direction-dependent self-regulated motion toward the light at T > T We develop approaches to create patterned arrays of microstructures with encoded multiple area-specific deformation modes and show their functions in responsive release of cargo, image concealment, and light-controlled reflectivity. We foresee that this platform can be widely applied in switchable adhesion, information encryption, autonomous antennae, energy harvesting, soft robotics, and smart buildings.
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http://dx.doi.org/10.1073/pnas.1811823115 | DOI Listing |
Alzheimers Dement
December 2024
Imaging Genetics Center, Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Marina del Rey, California, USA.
Introduction: Diffusion-weighted magnetic resonance imaging (dMRI) is sensitive to the microstructural properties of brain tissues and shows great promise in detecting the effects of degenerative diseases. However, many approaches analyze single measures averaged over regions of interest without considering the underlying fiber geometry.
Methods: We propose a novel macrostructure-informed normative tractometry (MINT) framework to investigate how white matter (WM) microstructure and macrostructure are jointly altered in mild cognitive impairment (MCI) and dementia.
Clin Neuroradiol
December 2024
Université Lyon I, Université Claude Bernard, Lyon, France.
Purpose: This study aimed to characterize spinal cord microstructure in healthy subjects using high angular resolution diffusion imaging (HARDI) and tractography.
Methods: Forty-nine healthy subjects (18-50 years, divided into 2 age groups) were included in a prospective study. HARDI of the cervical spinal cord were acquired using a 3T MRI scanner with: 64 directions, b‑value: 1000s/mm, reduced field-of-view (zonally magnified oblique multi-slice), and opposed phase-encoding directions.
Int J Mol Sci
November 2024
Blood Sciences (Pathology), James Cook University Hospital, Middlesbrough TS4 3BW, UK.
This study explores how select microRNAs (miRNAs) influence bone structure in humans and in transgenic mice. In trabecular bone biopsies from 84 postmenopausal women (healthy, osteopenic, and osteoporotic), we demonstrate that (deleted in lymphocytic leukemia 2)-encoded is strongly positively associated with bone mineral density (BMD) at different skeletal sites. In bone transcriptome analyses, levels correlated positively with the osteocyte characteristic transcripts (encoding sclerostin) and (Matrix Extracellular Phosphoglycoprotein), while the related showed a negative association with BMD and osteoblast markers.
View Article and Find Full Text PDFPhys Rev Lett
November 2024
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, Jiangsu Physical Science Research Center, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China.
Adv Mater
December 2024
National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, and Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, China.
Physical unclonable functions (PUFs) are emerging as a cutting-edge technology for enhancing information security by providing robust security authentication and non-reproducible cryptographic keys. Incorporating renewable and biocompatible materials into PUFs ensures safety for handling, compatibility with biological systems, and reduced environmental impact. However, existing PUF platforms struggle to balance high encoding capacity, diversified encryption signatures, and versatile functionalities with sustainability and biocompatibility.
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