The room-temperature coercivity, $H_C,$ and squareness, $M_R{\mathrm{/M}}_S$ (remanence/saturation magnetizations), of permanent magnet, ${\mathrm{SmCo}}_{\mathrm{5}}$ powders have been enhanced by ball milling with antiferromagnetic NiO (with Néel temperature, $T_N\text{=590\hspace{0.05em}}\mathrm{K}\mathrm{).}$ This enhancement is observed in the as-milled state. However, when the milling of ${\mathrm{SmCo}}_{\mathrm{5}}$ is carried out with an antiferromagnet with $T_N$ below room temperature (e.g., for CoO, $T_N\text{=290\hspace{0.05em}}\mathrm{K}\mathrm{),}$ the coercivity enhancement is only observed at low temperatures after field cooling through $T_N.$ The ferromagnetic–antiferromagnetic exchange coupling induced either by local heating during milling $({\mathrm{SmCo}}_{\mathrm{5}}\mathrm{+NiO})$ or field cooling $({\mathrm{SmCo}}_{\mathrm{5}}\mathrm{+CoO})$ is shown to be the origin of the $H_C$ increase.

Susceptibility, high-field magnetization, and submillimeter-wave electron spin resonance measurements of layered quasistoichiometric ${\mathrm{Li}}_{1-x}{\mathrm{Ni}}_{1+x}{\mathrm{O}}_2$ are reported and compared to isomorphic ${\mathrm{NaNiO}}_2.$ A mechanism of magnetic frustration induced by the excess Ni ions always present in the Li layers is proposed. We finally comment on the possible realization of an orbital liquid state in this controversial compound.

Improved glycemic control with insulin pump therapy in patients with type 1 diabetes mellitus has shown gradual reductions in nephropathy and retinopathy. More recently, the emerging concept of the artificial pancreas, comprising an insulin pump coupled to a continuous glucose meter and a control algorithm, would become the next major breakthrough in diabetes care. The patient safety and the efficiency of the therapy are directly derived from the delivery accuracy of rapid-acting insulin. For this purpose, a specific precision-oriented design of micropump has been built. The device, made of a stack of three silicon wafers, comprises two check valves and a pumping membrane that is actuated against stop limiters by a piezo actuator. Two membranes comprising piezoresistive strain gauges have been implemented to measure the pressure in the pumping chamber and at the outlet of the pump. Their high sensitivity makes possible the monitoring of the pumping accuracy with a tolerance of ±5% for each individual stroke of 200 nL. The capability of these sensors to monitor priming, reservoir overpressure, reservoir emptying, outlet occlusion and valve leakage has also been studied.