Microfabricated multi-turn gradient coils for microscale flow imaging

In this paper, we report the development of a multi-turn gradient coil assembly suitable for microscale static and flow imaging using magnetic resonance imaging (MRI) techniques. A novel microfabrication technique to manufacture the gradient coils is presented. The triaxial gradient assembly has gradient sensitivities exceeding 0.044 T/(mmiddotA) over a spherical region with a diameter of 4 mm. A time-of-flight flow measurement was obtained using these gradients to measure the velocity profile inside a capillary tube with a diameter of 1.67 mm at a spatial resolution of 47 mum.