Referred Journal Publications – By Topic

MEMS/NEMS Electrospray/Electrospinning Devices

• Olvera-Trejo and L. F. Velásquez-García, “Additively manufactured MEMS multiplexed coaxial electrospray sources for high-throughput, uniform generation of core-shell microparticles”, accepted for publication, Lab on a Chip (2016), DOI: 10.1039/c6lc00729e.
• J. Ponce de Leon and L. F. Velásquez-García, “Optimization of capillary flow through open-microchannel and open-micropillar arrays”, Journal of Physics D – Applied Physics, Vol. 49, No. 5, 055501 (13pp), 2016.
• L. F. Velásquez-García, “SLA 3D-printed arrays of miniaturized, internally-fed, polymer electrospray emitters”, Journal of Microelectromechanical Systems, Vol. 24, No. 6, pp. 2117 – 2127, 2015.
• P. Ponce de Leon, F. A. Hill, E. V. Heubel, and L. F. Velásquez-García,“Parallel Nanomanufacturing via Electrohydrodynamic Jetting from Microfabricated Externally-Fed Emitter Arrays”, Nanotechnology, Vol. 26, No. 22, 225301 (10pp), 2015. Paper was the featured article and cover of the issue 22, volume 26 of the IOP Journal Nanotechnology.
• F. A. Hill, E. V. Heubel, P. Ponce de Leon, and L. F. Velásquez-García, “High-Throughput Ionic Liquid Ion Sources Using Arrays of Microfabricated Electrospray Emitters with Integrated Extractor Grid and Carbon Nanotube Flow Control Structures”,  Journal of Microelectromechanical Systems, Vol. 23, No. 5, pp. 1237 – 1248, 2014. Paper was selected as one of the three JMEMS RightNow Papers of the Oct 2014 issue of JMEMS, in recognition of its excellent quality, effectively ranking it within the top 10% of the articles of the bi-monthly issue.
• B. Gassend, L. F. Velásquez-García, A. I. Akinwande and M. Martinez-Sanchez, “A Microfabricated Planar Electrospray Array Ionic Liquid Ion Source with Integrated Extractor,” Journal of Microelectromechanical Systems, Vol. 18, No. 3, pp. 679 – 694, 2009.
• L. F. Velásquez-García, A. I. Akinwande, and M. Martínez–Sánchez, “A Micro-fabricated Linear Array of Electrospray Emitters for Thruster Applications,” Journal of Microelectromechanical Systems, Vol. 15, No. 5, pp. 1260–1271, 2006.
• L. F. Velásquez-García, A. I. Akinwande, and M. Martínez–Sánchez, “A Planar Array of Micro-fabricated Electrospray Emitters for Thruster Applications,” Journal of Microelectromechanical Systems, Vol. 15, No. 5, pp. 1272–1280, 2006.

Ultrafast Field Emission Electron Sources

• C. Dong, M. E. Swanwick, D. Keithley, F. X. Kärtner, and L. F. Velásquez-García, “Multiplexing and Scaling-Down of Nanostructured, Photon-Triggered Silicon Field Emitter Arrays for Maximum Total Electron Yield”, IOP Nanotechnology, Vol. 26, No. 26, 265202 (11pp) 2015.
• R. G. Hobbs, Y. Yang, P. D. Keathley, M. E. Swanwick, L. F. Velásquez-García, F. X. Kärtner, W. S. Graves, and K. K. Berggren, “High-Density Au Nanorod Optical Field-Emitter Arrays”, Nanotechnology, Vol. 25, No. 46, 465304 (7pp), 2014.
• M. E. Swanwick, P. D. Keathley, A. Fallahi, P. R. Krogen, G. Laurent, F. X. Kärtner, and L. F. Velásquez-García, “Nanostructured Ultrafast Silicon-Tip Optical Field Emitter Arrays”, Nano Letters, Vol. 14, No. 9, pp. 5035 – 5043, 2014.
• P. D. Keithley, A. Sell, W. P. Putnam, S. Guerrera, L. F. Velásquez-García, and F. X. Kärtner, “Strong-Field Photo-Emission From Silicon Field Emitter Arrays”, Annalen Der Physik, Vol. 525, No. 1-2, pp. 144 – 150, 2013. Paper was the frontispiece of the volume 525 issue 1-2 of the Journal Annalen Der Physik.

MEMS Plasma Devices

• E. V. Heubel and L. F. Velásquez-García, “Microfabricated Retarding Potential Analyzers With Enforced Aperture Alignment for Improved Ion Energy Measurements in Plasmas”, Journal of Microelectromechanical Systems, Vol. 24, No. 5, pp. 1355 – 1369, 2015.
• E. F. C. Chimamkpam, E. S. Field, A. I. Akinwande, and L. F. Velásquez-García, “Resilient Batch-Fabricated Planar Arrays of Miniaturized Langmuir Probes for Real-Time Measurement of Plasma Potential Fluctuations in the HF to Microwave Frequency Range”, Journal of Microelectromechanical Systems, Vol. 23, No. 5, pp. 1131 – 1140, 2014.

MEMS Quadrupole Mass Filters

• K. Cheng, L. F. Velásquez-García, and A. I. Akinwande, “Chip-Scale Quadrupole Mass Filters for Portable Mass Spectrometry,” Journal of Microelectromechanical Systems, Vol. 19 No. 3, pp. 469–483, 2010.
• T. J. Hogan, S. Taylor, K. Cheung, L. F. Velásquez-García, A. I. Akinwande, and R. E. Pedder, “Performance Characteristics of a MEMS Quadrupole Mass Filter with Square Electrodes – Experimental and Simulated Results”, IEEE Transactions on Instrumentation and Measurement, Vol. 59, No. 9, pp. 2458-2467, Sept. 2010.
• L. F. Velásquez-García, K. Cheung, and A. I. Akinwande, “An Application of 3D MEMS Packaging: Out-Of-Plane Quadrupole Mass Filters,” Journal of Microelectromechanical Systems, Vol. 16, No. 6, pp. 1430–1438, 2008.

Novel Fabrication/Packaging Technologies for MEMS/NEMS

• A. P. Taylor and L. F. Velásquez-García, “Electrospray-printed nanostructured graphene oxide gas sensors”, Nanotechnology, Vol. 26, No. 50, 505301 (8pp), 2015.
• B. Gassend, L. F. Velásquez-García, and A. I. Akinwande, “Design and Fabrication of DRIE-Patterned Complex Needle-Like Structures,” Journal of Microelectromechanical Systems, Vol. 19, No. 3, pp. 589–598, 2010.
• B. Gassend, L. F. Velásquez-García, and A. I. Akinwande, “Precision In-Plane Hand Assembly of Bulk-Microfabricated Components for High Voltage MEMS Arrays Applications,” Journal of Microelectromechanical Systems, Vol. 18, No. 2, pp. 332 – 326, 2009.
• L. F. Velásquez-García and A. I. Akinwande, “Fabrication of Large Arrays of High-Aspect-Ratio, Single Crystal Silicon Columns with Isolated vertically Aligned Multi-Walled Carbon Nanotube Tips,”IOP Nanotechnology 19, (2008) 405305. Paper was the featured article and cover of the issue 40, volume 19 of the IOP Journal Nanotechnology.
• L. F. Velásquez-García, A. I. Akinwande and M. Martínez-Sánchez, “Precision Hand Assembly of MEMS subsystems using DRIE-patterned deflection Spring Structures: An Example of an Out-of-plane Substrate Assembly,” Journal of Microelectromechanical Systems, Vol. 16, No. 3, pp. 598–612, 2007.

MEMS/NEMS Vacuum Pumps

• Basu and L. F. Velásquez-García, “Electrostatic ion pump with nanostructured Si field emission electron source and Ti particle collectors for supporting ultra-high vacuum in miniaturized atom interferometry systems”, Journal of Micromechanics and Microengineering, Vol. 26, No. 12, 124003 (10pp), 2016.

MEMS/NEMS X-ray Sources

• A. Basu, M. E. Swanwick, A. A. Fomani, and L. F. Velásquez-García, “A Portable X-ray Source With a Nanostructured Pt-coated Silicon Field Emission Cathode for Absorption Imaging of low-Z Materials”, Journal of Physics D – Applied Physics, Vol. 48, No. 22, 225501 (11pp), 2015.
• S. Cheng, F. A. Hill, E. V. Heubel, and L. F. Velásquez- García “Low-Bremsstrahlung X-ray Source Using a Low-Voltage High-Current-Density Nanostructured Field Emission Cathode and a Transmission Anode for Markerless Soft Tissue Imaging”, Journal of Microelectromechanical Systems, Vol. 24, No. 2, pp. 373 – 383, 2015. Paper was selected as one of the three JMEMS RightNow Papers of the Apr 2015 issue of JMEMS, in recognition of its excellent quality, effectively ranking it within the top 10% of the articles of the bi-monthly issue.

MEMS/NEMS Gas Ionizers

• A. A. Fomani, L. F. Velásquez-García, and A. I. Akinwande, “Low-voltage Field Ionization of Gases up to Torr-level Pressures using Massive Arrays of Self-aligned Gated Nano-scale Tips”, IEEE Transactions on Electron Devices, Vol. 61, No. 5, pp. 1520 – 1528, 2014.
• L.-Y. Chen, L. F. Velásquez-García, X. Wang, K. Cheung, K. Teo, and A. I. Akinwande, “A Microionizer for Portable Mass Spectrometers using Double-Gated Isolated Vertically Aligned Carbon Nanofiber Arrays,” IEEE Transactions in Electron Devices, Vol. 58. No. 7, pp. 2149-2158, 2011.
• L. F. Velásquez-García, B. Gassend, and A. I. Akinwande,“CNT-based MEMS Ionizers for Portable Mass Spectrometry Applications,”Journal of Microelectromechanical Systems, Vol. 19, No. 3, pp. 484–493, 2010.

High-Current Field Emission Cathodes

• A. A. Fomani, L. F. Velásquez-García, and A. I. Akinwande, “Toward Amp-level Field Emission with Large-area Arrays of Pt-coated Self-aligned Gated Nano-scale Tips”, IEEE Transactions in Electron Devices, Vol. 61, No. 7, pp. 2538 – 2546, 2014.
• S. Guerrera, L. F. Velásquez-García, and A. I. Akinwande, “Scaling of High-Aspect-Ratio Current Limiters for the Individual Ballasting of Large Arrays of Field Emitters”, IEEE Transactions on Electron Devices, Vol. 59, pp. 2524 – 2530, 2012.
• L. F. Velásquez-García, S. Guerrera, Y. Niu, and A. I. Akinwande,”Uniform High-Current Cathodes Using Massive Arrays of Si Field Emitters Individually Controlled by Vertical Si Ungated FETs—Part 2: Device Fabrication and Characterization“, IEEE Transactions in Electron Devices, Vol. 58. No. 6, pp. 1783-1791, 2011.
• L. F. Velásquez-García, S. Guerrera, Y. Niu, and A. I. Akinwande,”Uniform High-Current Cathodes Using Massive Arrays of Si Field Emitters Individually Controlled by Vertical Si Ungated FETs—Part 1: Device Design and Simulation“, IEEE Transactions in Electron Devices, Vol. 58. No. 6, pp. 1775-1782, 2011.

MEMS Chemical Reactors

• F. Eid, L. F. Velásquez-García, and C. Livermore, “Design, Fabrication, and Demonstration of a MEMS Steam Generator for Ejector Pump Applications,” Journal of Micromechanics and Microengineering, Vol. 20, No. 20, 104007. Paper won best student oral paper award in Power MEMS 2009.
• B. A. Wilhite, K. F. Jensen, T. F. Hill, L. F. Velásquez-García, A. H. Epstein, and C. Livermore, “Design of a Silicon- Based Microscale Trickle-Bed System for Singlet-Oxygen Production,” American Institute of Chemical Engineering Journal, Vol. 54, No. 9, pp 2441 – 2455, 2008.
• L. F. Velásquez-García, T. F. Hill, B. A. Wilhite, K. F. Jensen, A. H. Epstein, and C. Livermore, “A MEMS Singlet Oxygen Generator – Part I: Device Fabrication and Proof of Concept Demonstration,” Journal of Microelectromechanical Systems, Vol. 16, No. 6, pp. 1482 – 1491, 2007.
• T. F. Hill, L. F. Velásquez-García, B. A. Wilhite, W. T. Rawlins, S. Lee, K. F. Jensen, A. H. Epstein, and C. Livermore, “A MEMS Singlet Oxygen Generator – Part II: Experimental Exploration of the Performance Space,” Journal of Microelectromechanical Systems, Vol. 16, No. 6, pp. 1492 – 1505, 2007.

MEMS Tactile Displays

• X. Xie, Y. Zaitsev, L. F. Velásquez-García, S. J. Teller, and C. Livermore, “Scalable, MEMS-Enabled, Vibrational Tactile Actuators for High Resolution Tactile Displays”, Journal of Micromechanics and Microengineering, Vol. 24, No. 12, 125014 (11pp), 2014.