57,467 research outputs found
A foreign body response-on-a-chip platform
Understanding the foreign body response (FBR) and desiging strategies to modulate such a response represent a grand challenge for implant devices and biomaterials. Here, the development of a microfluidic platform is reported, i.e., the FBR?on?a?chip (FBROC) for modeling the cascade of events during immune cell response to implants. The platform models the native implant microenvironment where the implants are interfaced directly with surrounding tissues, as well as vasculature with circulating immune cells. The study demonstrates that the release of cytokines such as monocyte chemoattractant protein 1 (MCP?1) from the extracellular matrix (ECM)?like hydrogels in the bottom tissue chamber induces trans?endothelial migration of circulating monocytes in the vascular channel toward the hydrogels, thus mimicking implant?induced inflammation. Data using patient?derived peripheral blood mononuclear cells further reveal inter?patient differences in FBR, highlighting the potential of this platform for monitoring FBR in a personalized manner. The prototype FBROC platform provides an enabling strategy to interrogate FBR on various implants, including biomaterials and engineered tissue constructs, in a physiologically relevant and individual?specific manner
Experimental multiphase estimation on a chip
Multiparameter estimation is a general problem that aims at measuring unknown
physical quantities, obtaining high precision in the process. In this context,
the adoption of quantum resources promises a substantial boost in the
achievable performances with respect to the classical case. However, several
open problems remain to be addressed in the multiparameter scenario. A crucial
requirement is the identification of suitable platforms to develop and
experimentally test novel efficient methodologies that can be employed in this
general framework. We report the experimental implementation of a
reconfigurable integrated multimode interferometer designed for the
simultaneous estimation of two optical phases. We verify the high-fidelity
operation of the implemented device, and demonstrate quantum-enhanced
performances in two-phase estimation with respect to the best classical case,
post-selected to the number of detected coincidences. This device can be
employed to test general adaptive multiphase protocols due to its high
reconfigurability level, and represents a powerful platform to investigate the
multiparameter estimation scenario.Comment: 10+7 pages, 7+4 figure
Cold molecular ions on a chip
We report the sympathetic cooling and Coulomb crystallization of molecular
ions above the surface of an ion-trap chip. N and CaH ions were
confined in a surface-electrode radiofrequency ion trap and cooled by the
interaction with laser-cooled Ca ions to secular translational
temperatures in the millikelvin range. The configuration of trapping potentials
generated by the surface electrodes enabled the formation of planar bicomponent
Coulomb crystals and the spatial separation of the molecular from the atomic
ions on the chip. The structural and thermal properties of the Coulomb crystals
were characterized using molecular dynamics simulations. The present study
extends chip-based trapping techniques to Coulomb-crystallized molecular ions
with potential applications in mass spectrometry, cold chemistry, quantum
information science and spectroscopy.Comment: 5 pages, 4 figure
A Stark decelerator on a chip
A microstructured array of 1254 electrodes on a substrate has been configured
to generate an array of local minima of electric field strength with a
periodicity of 120 m about 25 m above the substrate. By applying
sinusoidally varying potentials to the electrodes, these minima can be made to
move smoothly along the array. Polar molecules in low-field seeking quantum
states can be trapped in these traveling potential wells. Recently, we
experimentally demonstrated this by transporting metastable CO molecules at
constant velocities above the substrate [Phys. Rev. Lett. 100 (2008) 153003].
Here, we outline and experimentally demonstrate how this microstructured array
can be used to decelerate polar molecules directly from a molecular beam. For
this, the sinusoidally varying potentials need to be switched on when the
molecules arrive above the chip, their frequency needs to be chirped down in
time, and they need to be switched off before the molecules leave the chip
again. Deceleration of metastable CO molecules from an initial velocity of 360
m/s to a final velocity as low as 240 m/s is demonstrated in the 15-35 mK deep
potential wells above the 5 cm long array of electrodes. This corresponds to a
deceleration of almost , and about 85 cm of kinetic energy is
removed from the metastable CO molecules in this process.Comment: 17 pages, 6 figure
Continuous variable entanglement on a chip
Encoding quantum information in continuous variables (CV)---as the quadrature
of electromagnetic fields---is a powerful approach to quantum information
science and technology. CV entanglement---light beams in
Einstein-Podolsky-Rosen (EPR) states---is a key resource for quantum
information protocols; and enables hybridisation between CV and single photon
discrete variable (DV) qubit systems. However, CV systems are currently limited
by their implementation in free-space optical networks: increased complexity,
low loss, high-precision alignment and stability, as well as hybridisation,
demand an alternative approach. Here we show an integrated photonic
implementation of the key capabilities for CV quantum technologies---generation
and characterisation of EPR beams in a photonic chip. Combined with integrated
squeezing and non-Gaussian operation, these results open the way to universal
quantum information processing with light
Proteomics-on-a-chip for Biomarker discovery
In proteomics research still two-dimensional gel electrophoresis (2D-GE) is currently used for biomarker discovery. We applied free flow electrophoresis (FFE) separation technology combined with biomolecular interaction sensing using Surface Plasmon Resonance (SPR) imaging in an integrated proteomics-on-a-chip device as a proof of concept for biomarker discovery
Fiber-coupled erbium microlasers on a chip
An erbium-doped, toroid-shaped microlaser fabricated on a silicon chip is described and characterized. Erbium-doped sol-gel films are applied to the surface of a silica toroidal microresonator to create the microcavity lasers. Highly confined whispering gallery modes make possible single-mode and ultralow threshold microlasers
Polarization entangled state measurement on a chip
The emerging strategy to overcome the limitations of bulk quantum optics
consists of taking advantage of the robustness and compactness achievable by
the integrated waveguide technology. Here we report the realization of a
directional coupler, fabricated by femtosecond laser waveguide writing, acting
as an integrated beam splitter able to support polarization encoded qubits.
This maskless and single step technique allows to realize circular transverse
waveguide profiles able to support the propagation of Gaussian modes with any
polarization state. Using this device, we demonstrate the quantum interference
with polarization entangled states and singlet state projection.Comment: Revtex, 5+2 pages (with supplementary information), 4+1 figure
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