Full text loading...
NSMT fabrication and characterization. (a) Process flow for making NSMT. (b) Variation of magnetization vs. the applied magnetic field for the NSMT fabricated 1 nm and 30 nm Ni films. (c)–(d) SEM images of NSMT fabricated sputtering 30 nm Ni film and shrinking. (e) SEM cross section of NSMT fabricated by sputtering 1 nm Ni film on PO. (f) EDX data for elemental composition of both 1 nm and 30 nm NSMT.
Simulation and AFM-MFM results. (a) 3D AFM scan of 30 nm Ni NSMT. (b) A 7 × 7 μm scan of the 30 nm NSMT. (c) Height profile of the A-B line from figure (b). (d) Simulated magnetic field gradient in the z direction. (e) Calculated magnetic field gradient variation with distance between NSMT and with size of NSMT. (f) AFM measurements and corresponding MFM results for NSMT fabricated using 30 nm Ni film.
Fabrication of NSMT integrated microfluidic device. (a) Steps of fabrication and modes of operation. The device consists of three PO layers: a top layer (i), a channel layer (ii), and bottom layer (iii) containing the NSMT. The top layer is single sheet of PO to seal the channel. Channels were designed using CAD software and cut in PO using a laser cutter before the film was shrunk. To create the NSMT layer, 1 nm or 30 nm nickel was sputter coated on pre-stressed PO. The three layers were then aligned (iv) and secured using 0.4 mm pins (v). Layers were then heated to 155 °C to bond them together and form the device. The extraction mode is indicated in vii. The collection mode is indicated in viii. (b) Indicates the variation of fluorescence vs. time in extraction mode. Fluorescence was recorded while flowing 1 μm fluorescent magnetic beads through the microfluidic device. (c) Purity vs. flow rate for 1% magnetic bead and 99% polystyrene bead mixture. (d) Variation of enrichment vs. % magnetic beads.
DNA extraction with NMST for qPCR. (a) Process flow of sample preparation in 96 well plate format. NMST substrates were fabricated on shrink film as previously described but then taped to the bottom of the bottomless well plate. (b) Actual device, with the NMST at the bottom of a 96 well plate and T magnetic underneath. (c) Calculated DNA concentration that NSMT trapped versus the positive control Qiagen and the negative control of external magnet only (no NMST). Method is further described in supplemental section.
Article metrics loading...