CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numero...CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numerous representations in popular media.This attention highlights the enormous interest in and potential of this technology for biomedical applications,such as cargo delivery,diagnostics,and minimally invasive surgery,as well as for applications in microfluidics and manufacturing.To achieve the collective behavior and control required for microswimmers to effectively perform such actions within complex,in vivo and microfluidic environments,they must meet a strict set of engineering criteria.These requirements include,but are not limited to,small size,structural monodispersity,flexibility,biocompatibility,and multifunctionality.Additionally,microswimmers must be able to adapt to delicate environments,such as human vasculature,while safely performing preprogrammed tasks in response to chemical and mechanical signals.Naturally information-bearing biopolymers,such as peptides,RNA,and DNA,can provide programmability,multifunctionality,and nanometer-scale precision for manufactured structures.In particular,DNA is a useful engineering material because of its predictable and well-characterized material properties,as well as its biocompatibility.Moreover,recent advances in DNA nanotechnology have enabled unprecedented abilities to engineer DNA nanostructures with tunable mechanics and responsiveness at nano-and micrometer scales.Incorporating DNA nanostructures as subcomponents in microswimmer systems can grant these structures enhanced deformability,reconfigurability,and responsiveness to biochemical signals while maintaining their biocompatibility,providing a versatile pathway for building programmable,multifunctional microand nanoscale machines with robotic capabilities.In this Account,we highlight our recent progress toward the experimental realization of responsive microswimmers made with compliant DNA components.We present a hybrid top-down,bottom-up fabrication method that combines templated assembly with structural DNA nanotechnology to address the manufacturing limitations of flexibly linked microswimmers.Using this method,we construct microswimmers with enhanced structural complexity and more controlled particle placement,spacing,and size,while maintaining the compliance of their DNA linkage.We also present a novel experimental platform that utilizes two-photon polymerization(TPP)to fabricate millimeter-scale swimmers(milliswimmers)with fully customizable shapes and integrated flexible linkers.This platform addresses limitations related to population-level heterogeneity in micrometer-scale systems,allowing us to isolate the effects of milliswimmer designs from variations in their physical dimensions.Using this platform,we interrogate established hydrodynamic models of microswimmer locomotion and explore how design and actuation parameters influence milliswimmer velocity.We next explore opportunities for enhancing microswimmer responsiveness,functionality,and physical intelligence through the inclusion of nucleic acid subcomponents.Finally,we highlight how our parallel research on xeno nucleic acids and interfacing DNA nanotechnology with living cells can enable the creation of fully organic,truly biocompatible microswimmers with enhanced functionality,improving the viability of microswimmers for applications in healthcare,manufacturing,and synthetic biology.展开更多
The ability to precisely control the excitation of phonon polaritons(PhPs)provides unique opportunities for various nanophotonic applications,such as on-chip optical communication,quantum information processing,and co...The ability to precisely control the excitation of phonon polaritons(PhPs)provides unique opportunities for various nanophotonic applications,such as on-chip optical communication,quantum information processing,and controlled thermal radiation.Recently,ghost hyperbolic phonon polaritons(g-HPs)have been discovered,which exhibit in-plane hyperbolic dispersion on the surface and oblique wavefronts in the bulk.These g-HPs exhibit long-range,ray-like propagation,which is highly desirable.However,selective excitation of polaritonic modes and flexible control over the directionality of g-HPs remains an open problem.In this work,we experimentally demonstrate that changing the shape of the launching micro/nano antenna allows for control over the polariton mode excitation.Using a single asymmetric triangular gold antenna fabricated on a calcite crystal surface,we showcase highly directional g-HP excitation through selectively exciting desirable polariton modes.Our near-field imaging experiments verify that the g-HP excited by the triangular antenna can propagate over 80 microns,which is consistent with our numerical predictions.Overall,by combining g-HP theory with structural engineering,our work has further developed the potential of such anisotropic materials,enabling unexpected control over g-HPs,thus opening opportunities for various applications in mid-IR optoelectronics.展开更多
基金supported in part by the National Science Foundation(NSF)grants 1739308(R.E.T.)2132886(R.E.T.),NSF GREP DGE1745016/DGE2140739(T.I.)a seed grant from the Carnegie Mellon University Manufacturing Futures Institute(R.E.T.and S.B.).
文摘CONSPECTUS:The concept of micrometer-scale swimming robots,also known as microswimmers,navigating the human body to perform robotic tasks has captured the public imagination and inspired researchers through its numerous representations in popular media.This attention highlights the enormous interest in and potential of this technology for biomedical applications,such as cargo delivery,diagnostics,and minimally invasive surgery,as well as for applications in microfluidics and manufacturing.To achieve the collective behavior and control required for microswimmers to effectively perform such actions within complex,in vivo and microfluidic environments,they must meet a strict set of engineering criteria.These requirements include,but are not limited to,small size,structural monodispersity,flexibility,biocompatibility,and multifunctionality.Additionally,microswimmers must be able to adapt to delicate environments,such as human vasculature,while safely performing preprogrammed tasks in response to chemical and mechanical signals.Naturally information-bearing biopolymers,such as peptides,RNA,and DNA,can provide programmability,multifunctionality,and nanometer-scale precision for manufactured structures.In particular,DNA is a useful engineering material because of its predictable and well-characterized material properties,as well as its biocompatibility.Moreover,recent advances in DNA nanotechnology have enabled unprecedented abilities to engineer DNA nanostructures with tunable mechanics and responsiveness at nano-and micrometer scales.Incorporating DNA nanostructures as subcomponents in microswimmer systems can grant these structures enhanced deformability,reconfigurability,and responsiveness to biochemical signals while maintaining their biocompatibility,providing a versatile pathway for building programmable,multifunctional microand nanoscale machines with robotic capabilities.In this Account,we highlight our recent progress toward the experimental realization of responsive microswimmers made with compliant DNA components.We present a hybrid top-down,bottom-up fabrication method that combines templated assembly with structural DNA nanotechnology to address the manufacturing limitations of flexibly linked microswimmers.Using this method,we construct microswimmers with enhanced structural complexity and more controlled particle placement,spacing,and size,while maintaining the compliance of their DNA linkage.We also present a novel experimental platform that utilizes two-photon polymerization(TPP)to fabricate millimeter-scale swimmers(milliswimmers)with fully customizable shapes and integrated flexible linkers.This platform addresses limitations related to population-level heterogeneity in micrometer-scale systems,allowing us to isolate the effects of milliswimmer designs from variations in their physical dimensions.Using this platform,we interrogate established hydrodynamic models of microswimmer locomotion and explore how design and actuation parameters influence milliswimmer velocity.We next explore opportunities for enhancing microswimmer responsiveness,functionality,and physical intelligence through the inclusion of nucleic acid subcomponents.Finally,we highlight how our parallel research on xeno nucleic acids and interfacing DNA nanotechnology with living cells can enable the creation of fully organic,truly biocompatible microswimmers with enhanced functionality,improving the viability of microswimmers for applications in healthcare,manufacturing,and synthetic biology.
基金support from ANU PhD student scholarship,Australian Research Council(ARC,numbers DP220102219,DP240101011,LE230100113,LE200100032)the National Health and Medical Research Council(NHMRC,ID:GA275784)ARC Centre of Excellence in Quantum Computation and Communication Technology(CE170100012).
文摘The ability to precisely control the excitation of phonon polaritons(PhPs)provides unique opportunities for various nanophotonic applications,such as on-chip optical communication,quantum information processing,and controlled thermal radiation.Recently,ghost hyperbolic phonon polaritons(g-HPs)have been discovered,which exhibit in-plane hyperbolic dispersion on the surface and oblique wavefronts in the bulk.These g-HPs exhibit long-range,ray-like propagation,which is highly desirable.However,selective excitation of polaritonic modes and flexible control over the directionality of g-HPs remains an open problem.In this work,we experimentally demonstrate that changing the shape of the launching micro/nano antenna allows for control over the polariton mode excitation.Using a single asymmetric triangular gold antenna fabricated on a calcite crystal surface,we showcase highly directional g-HP excitation through selectively exciting desirable polariton modes.Our near-field imaging experiments verify that the g-HP excited by the triangular antenna can propagate over 80 microns,which is consistent with our numerical predictions.Overall,by combining g-HP theory with structural engineering,our work has further developed the potential of such anisotropic materials,enabling unexpected control over g-HPs,thus opening opportunities for various applications in mid-IR optoelectronics.
