Metamaterials hold great potential to enhance the imaging performance of magnetic resonance imaging(MRI)as auxiliary devices,due to their unique ability to confine and enhance electromagnetic fields.Despite their prom...Metamaterials hold great potential to enhance the imaging performance of magnetic resonance imaging(MRI)as auxiliary devices,due to their unique ability to confine and enhance electromagnetic fields.Despite their promise,the current implementation of metamaterials faces obstacles for practical clinical adoption due to several notable limitations,including their bulky and rigid structures,deviations from optimal resonance frequency,and inevitable interference with the radiofrequency(RF)transmission field in MRI.Herein,we address these restrictions by introducing a flexible and smart metamaterial that enhances sensitivity by conforming to patient anatomies while ensuring comfort during MRI procedures.The proposed metamaterial selectively amplifies the magnetic field during the RF reception phase by passively sensing the excitation signal strength,remaining“off”during the RF transmission phase.Additionally,the metamaterial can be readily tuned to achieve a precise frequency match with the MRI system through a controlling circuit.The metamaterial presented here paves the way for the widespread utilization of metamaterials in clinical MRI,thereby translating this promising technology to the MRI bedside.展开更多
Diatoms are unicellular,photosynthetic algae that are ubiquitous in aquatic environments.Their unique,three-dimensional(3D)structured silica exoskeletons,also known as frustules,have drawn attention from a variety of ...Diatoms are unicellular,photosynthetic algae that are ubiquitous in aquatic environments.Their unique,three-dimensional(3D)structured silica exoskeletons,also known as frustules,have drawn attention from a variety of research fields due to their extraordinary mechanical properties,enormous surface area,and unique optical properties.Despite their promising use in a range of applications,without methods to uniformly control the frustules’alignment/orientation,their full potential in technology development cannot be realized.In this paper,we realized and subsequently modeled a simple bubbling method for achieving large-area,uniformly oriented Coscinodiscus species diatom frustules.With the aid of bubble-induced agitations,close-packed frustule monolayers were achieved on the water–air interface with up to nearly 90%of frustules achieving uniform orientation.The interactions between bubble-induced agitations were modeled and analyzed,demonstrating frustule submersion and an adjustment of the orientation during the subsequent rise towards the water’s surface to be fundamental to the experimentally observed uniformity.The method described in this study holds great potential for frustules’engineering applications in a variety of technologies,from sensors to energy-harvesting devices.展开更多
基金supported by the National Institutes of Health(NIH)of Biomedical Imaging and Bioengineering grant no.5R21EB024673-03the Rajen Kilachand Fund for Integrated Life Science and Engineering.
文摘Metamaterials hold great potential to enhance the imaging performance of magnetic resonance imaging(MRI)as auxiliary devices,due to their unique ability to confine and enhance electromagnetic fields.Despite their promise,the current implementation of metamaterials faces obstacles for practical clinical adoption due to several notable limitations,including their bulky and rigid structures,deviations from optimal resonance frequency,and inevitable interference with the radiofrequency(RF)transmission field in MRI.Herein,we address these restrictions by introducing a flexible and smart metamaterial that enhances sensitivity by conforming to patient anatomies while ensuring comfort during MRI procedures.The proposed metamaterial selectively amplifies the magnetic field during the RF reception phase by passively sensing the excitation signal strength,remaining“off”during the RF transmission phase.Additionally,the metamaterial can be readily tuned to achieve a precise frequency match with the MRI system through a controlling circuit.The metamaterial presented here paves the way for the widespread utilization of metamaterials in clinical MRI,thereby translating this promising technology to the MRI bedside.
基金This research is in part supported by the National Science Foundation(NSF ECCS-1202304).
文摘Diatoms are unicellular,photosynthetic algae that are ubiquitous in aquatic environments.Their unique,three-dimensional(3D)structured silica exoskeletons,also known as frustules,have drawn attention from a variety of research fields due to their extraordinary mechanical properties,enormous surface area,and unique optical properties.Despite their promising use in a range of applications,without methods to uniformly control the frustules’alignment/orientation,their full potential in technology development cannot be realized.In this paper,we realized and subsequently modeled a simple bubbling method for achieving large-area,uniformly oriented Coscinodiscus species diatom frustules.With the aid of bubble-induced agitations,close-packed frustule monolayers were achieved on the water–air interface with up to nearly 90%of frustules achieving uniform orientation.The interactions between bubble-induced agitations were modeled and analyzed,demonstrating frustule submersion and an adjustment of the orientation during the subsequent rise towards the water’s surface to be fundamental to the experimentally observed uniformity.The method described in this study holds great potential for frustules’engineering applications in a variety of technologies,from sensors to energy-harvesting devices.
