Voltage-driven, local, and efficient excitation of nitrogen-vacancy centers in diamond.

Magnetic sensing technology has found widespread application in a diverse set of industries including transportation, medicine, and resource exploration. These uses often require highly sensitive instruments to measure the extremely small magnetic fields involved, relying on difficult-to-integrate superconducting quantum interference devices and spin-exchange relaxation-free magnetometers. A potential alternative, nitrogen-vacancy (NV) centers in diamond, has shown great potential as a high-sensitivity and high-resolution magnetic sensor capable of operating in an unshielded, room-temperature environment. Transitioning NV center-based sensors into practical devices, however, is impeded by the need for high-power radio frequency (RF) excitation to manipulate them. We report an advance that combines two different physical phenomena to enable a highly efficient excitation of the NV centers: magnetoelastic drive of ferromagnetic resonance and NV-magnon coupling. Our work demonstrates a new pathway that combine acoustics and magnonics that enables highly energy-efficient and local excitation of NV centers without the need for any external RF excitation and, thus, could lead to completely integrated, on-chip, atomic sensors.

Morphological and Chemical Evolution of Gradually Deposited Diamond-Like Carbon Films on Polyethylene Terephthalate: From Subplantation Processes to Structural Reorganization by Intrinsic Stress Release Phenomena.

Diamond-like carbon (DLC) films on polyethylene terephthalate (PET) are nowadays intensively studied composites due to their excellent gas barrier properties and biocompatibility. Despite their applicative features being highly explored, the interface properties and structural film evolution of DLC coatings on PET during deposition processes are still sparsely investigated. In this study two different types of DLC films were gradually deposited on PET by radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) using acetylene plasma. The surface morphology of the deposited samples has been analyzed by atomic force microscopy (AFM). Their chemical composition was investigated by diffusive reflectance infrared Fourier transform (DRIFT) and Raman spectroscopy analysis and the surface wettability by contact angle measurements. Subplantation processes and interface effects are revealed through the morphological and chemical analysis of both types. During plasma deposition processes the increasing carbon load causes the rise of intrinsic film stress. It is proven that stress release phenomena cause the transition between polymer-like to a more cross-linked DLC network by folding dehydrogenated chains into closed 6-fold rings. These findings significantly lead to an enhanced understanding in DLC film growth mechanism by RF-PECVD processes.

Novel triphosphorylation polyurethane nanoparticles for blood-contacting biomaterials' coating.

Improving hemocompatibility of biomaterials and devices contacting the human blood has been the subject of intensive research. In this study, we synthesized a novel excellent blood compatible polyurethane/sodium triphosphate nanoparticle (PU/STPP). Characterization of polyurethane/sodium triphosphate (PU/STPP) nanoparticles was carried out by transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS), nuclear magnetic resonance (NMR), and energy dispersive spectroscopy (EDS). Blood compatibility assessment of PU/STPP nanoparticles was performed by in vitro coagulation time, plasma clotting time, hemolysis rate, and red blood cell morphology tests. Cell compatibility evaluations of PU/STPP nanoparticles were obtained by MTT cell viability tests. The PU/STPP nanoparticles also were used to modify vascular prostheses with cosedimentation. Platelet adhesion tests showed that blood compatibility of vascular prostheses coated with PU/STPP nanoparticles is better than that of pure vascular prostheses.