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Energy conservation and battery life extension are key challenges for the next-generation hybrid electric vehicles. In particular, the temperature and electric currents in a storage battery need to be monitored simultaneously with ∼1 kHz signal bandwidth for optimum battery usage. Here we introduce a centimeter-scale portable quantum sensor head, consisting of a diamond substrate hosting an ensemble of nitrogen-vacancy (NV) color centers with a density of ∼3 × 1017 cm−3. One diamond surface is attached to a multi-mode fiber for simultaneous optical excitation and readout of the NV centers, while the other diamond surface is attached to a coplanar microwave guide for NV spin ground-state mixing. Signal bandwidth of 1 kHz was realized through time-domain multiplexing of the two-tone microwave frequency modulation at 20 kHz. Two microwave frequencies were locked to the two resonance points that were determined from the optically detected magnetic resonance spectrum. From the mean and the difference of the deviation from the two locked frequencies, the temperature and magnetic field were obtained simultaneously and independently, with sensitivities of 3.5 nT/Hz1/2 and 1.3 mK/Hz1/2, respectively. We also showed that our sensor reached a minimum detectable magnetic field of 5 pT by accumulating signals for over 10 000 s. [ABSTRACT FROM AUTHOR]

An all-in-one wireless pump with a power generator was developed for use in biomedical applications. The developed pump is driven by an external rotating magnetic field. Thus, the performance of the system is limited by the magnetic properties of the rotor. To improve the magnetic properties of the magnetic all-in-one pump, a fully magnetic impeller was fabricated with magnetic powder (Sm2Fe17N3) because sintered magnetic materials have a lower degree of freedom for shape. The magnetic moment (M) and coercive force (Hc) of the fully magnetic impeller are 0.993 Am2 and 0.82 MA/m, respectively. We analyzed the magnetic properties of the fully magnetic impeller using simulation and experiments. In addition, we investigated the improved performance of the all-in-one pump system using the fully magnetic impeller. [ABSTRACT FROM AUTHOR]

This paper introduces an in-plane uniaxial anisotropy control method of Fe72Si14B14 magnetostrictive thin-film for high sensitivity of MI sensor. The anisotropy can be controlled by inverse-magnetostriction and inducing a bias stress using the difference of thermal expansion coefficient in bimetal structure. We can control the uniaxiality of anisotropy by the structure of the thin-film. Our proposed methods are useful in solving the problems and inconveniences of existing methods. To verify the proposed methods, we carried out experiments as well as FEM simulation. Looking at the FEM simulation and magnetic domain observation results, we confirmed that the in-plane uniaxial anisotropy could be controlled by a difference of a thermal expansion coefficient. Moreover, changes in the length of the conductive layer provides the local (edge section) control of the uniaxial anisotropy. [ABSTRACT FROM AUTHOR]