1. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. (a)Three-dimensional (3-D) model of the air amplifier where d1 and d2 are the depth and the width of the primary channel, respectively, and d3 is the depth of the secondary channel. (b) Schematic diagram and the principle of operation of the air amplifier. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

2. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. (a) 2-D ANSYS FLUENT simulation of the interior flow field. The inserted views show the nitrogen gas flow velocity contours in the near-wall region with the gap width of 30–50 μm (a), 70 μm (b) and 100 μm (c). All simulations were performed with a nitrogen pressure of 2 atm. (b) Velocity contours of the interior flow with a stable Coanda effect, and (c) without the Coanda effect as a result of the 3-D ANSYS FLUENT simulations. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

3. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. Process flow for the fabrication of the micromachined air amplifier; the SU-8 mould fabrication (1)–(7); the PDMS molding process (8)–(10); and the final PDMS air amplifier (11). (a) 3-D model of the SU-8 mold structure. (b) Photograph of the fabricated three- layer SU-8 mold structure (c) 3-D model of the cast structure of the PDMS air amplifier as a product of the molding process. (d) Photograph of the final device formed from two PDMS cast structures by a bonding process. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

4. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. Schematic diagram of the experimental apparatus. (1) syringe pump, (2) syringe, (3) capillary tubing, (4) T-union, (5) ES emitter, (6) air amplifier, (7) gap, (8) pressure regulating valve, (9) PTFE tube, (10) nitrogen bottle, (11) high voltage power source, (12) current probe, (13) charge meter. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

5. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. Measured ES current as a function of the nitrogen pressure P and the current probe distance L. The solution flow rate Q was 50 nL/min and the ES emitter offset d was 0 mm. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

6. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. Measured ES current as a function of the ES emitter offset d. The solution flow rate Q was 50 nL/min, the current probe position L was 4 mm and the nitrogen pressure P was 2 atm. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006

7. Date of download: 6/27/2016 Copyright © 2016 SPIE. All rights reserved. Measured ES current as a function of the solution flow rate. The ES emitter offset d was 0 mm, the current probe distance L was 4 mm, and the nitrogen pressure P was 2 atm. Figure Legend: From: Design, simulation, and fabrication of a MEMS-based air amplifier for electrospray ionization J. Micro/Nanolith. MEMS MOEMS. 2013;12(2):023006-023006. doi:10.1117/1.JMM.12.2.023006