Fig 1. ASAP based Rheometer.
(A) Computer generated 3D rendering of the experimental setup. The micro-fluidic channel is placed in between the C-shaped electromagnet core, and is imaged with the microscope objective. The intensity of the transmitted light from the light source is monitored using either a camera or photo diode (not shown). (B) Front view of the microfluidic chamber in between the magnetic poles. The face of the electromagnet is 10 mm X 10 mm and the gap is 16 mm. The magnet is tilted at a 10o angle from the horizontal. (C) A diagram showing the microfluidic chamber. The chamber has a height, H, of 250 um. The PDMS base and posts have a total height of 125 um so that the gap height, G, between the top of the posts and the ceiling of the channel is 125 um. The channel is 1 mm in width and 16 mm long. (D) SEM of an array of micro-posts. The posts are 2 um in diameter and 23 um tall. Nearest neighbor distance between posts varies between a few um and 15 um.