Prof. Nikhil A. Koratkar Profile

Prof. Nikhil A. Koratkar

Assistant Professor at Rensselaer Polytechnic Institute

SPIE Involvement:

Author

Proceedings Article | 31 March 2006 Paper

Hydrogen generation using ruthenium nano-rod array electrodes

Seongyul Kim, Tansel Karabacak, Toh-Ming Lu, Nikhil Koratkar

Proceedings Volume 6172, 61720B (2006) https://doi.org/10.1117/12.658786

KEYWORDS: Electrodes, Ruthenium, Hydrogen, Nanostructuring, Nanostructures, Hydrogen production, Nanolithography, Nickel, Resistance, Nanorods

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Proceedings Article | 15 March 2006 Paper

Preventing interfacial slip in carbon nanotube polycarbonate composites

Jonghwan Suhr, Nikhil Koratkar

Proceedings Volume 6169, 616912 (2006) https://doi.org/10.1117/12.658618

KEYWORDS: Composites, Single walled carbon nanotubes, Nanocomposites, Interfaces, Carbon nanotubes, Polymers, Scanning electron microscopy, Structural engineering, Mechanical engineering, Nanolithography

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Proceedings Article | 16 May 2005 Paper

Characterization of mechanical properties of multiwalled nanotube polymer composites

Jonghwan Suhr, Linda Schadler, Nikhil Koratkar

Proceedings Volume 5760, (2005) https://doi.org/10.1117/12.594567

KEYWORDS: Polymers, Nanocomposites, Composites, Carbon nanotubes, Interfaces, Scanning electron microscopy, Carbon, Nanolithography, Data storage, Aerospace engineering

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Proceedings Article | 16 May 2005 Paper

Nanostructured electrodes for efficient gas ionization

J. Singh, Toh-Ming Lu, Gwo-Ching Wang, Nikhil Koratkar

Proceedings Volume 5763, (2005) https://doi.org/10.1117/12.594571

KEYWORDS: Ionization, Argon, Electrodes, Ions, Silver, Nanostructuring, Tungsten, Chemical species, Gases, Nanorods

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Proceedings Article | 29 July 2004 Paper

Possibility of using carbon nanotubes as microactuators

Nikhil Koratkar, Ashish Modi, J. Kim, Bingqing Wei, S. Talapatra, Robert Vajtai, Pulickel Ajayan

Proceedings Volume 5389, (2004) https://doi.org/10.1117/12.532678

KEYWORDS: Electrodes, Single walled carbon nanotubes, Carbon nanotubes, Aluminum, Actuators, Fullerenes, Hydrogen, Silicon, Polymers, Carbon

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Proceedings Article | 29 July 2004 Paper

Damping characterization of carbon nanotube thin films

Jonghwan Suhr, Nikhil Koratkar, Pulickel Ajayan

Proceedings Volume 5386, (2004) https://doi.org/10.1117/12.532625

KEYWORDS: Carbon nanotubes, Epoxies, Thin films, Polymers, Silica, Composites, Gold, Polymer thin films, Chemical species, Nanowires

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Proceedings Article | 31 July 2003 Paper

Engineered connectivity in carbon nanotube films for damping applications

Eric Lass, Pulickel Ajayan, Nikhil Koratkar

Proceedings Volume 5052, (2003) https://doi.org/10.1117/12.483763

KEYWORDS: Composites, Carbon nanotubes, Scanning electron microscopy, Chemical vapor deposition, Polymer thin films, Polymers, Silica, Electroluminescence, Interfaces, Mechanics

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Proceedings Article | 22 July 2003 Paper

Power consumption of piezoelectric actuators with multiwalled carbon nanotube film deposition

Ashish Modi, Nikhil Koratkar

Proceedings Volume 5055, (2003) https://doi.org/10.1117/12.483570

KEYWORDS: Carbon nanotubes, Actuators, Scanning electron microscopy, Thin film coatings, Carbon, Image resolution, Polymers, Aerospace engineering, Manufacturing, Thin film deposition

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Proceedings Article | 15 July 2002 Paper

MEMS actuators for boundary layer control of micro-rotor blades

Nikhil Koratkar, Theodorian Borca-Tasciuc

Proceedings Volume 4701, (2002) https://doi.org/10.1117/12.474660

KEYWORDS: Actuators, Micro unmanned aerial vehicles, Microelectromechanical systems, Silicon, Ferroelectric materials, Skin, Surface roughness, Aerodynamics, Thin films, Fermium

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Proceedings Article | 11 July 2002 Paper

Energy-absorbent composites featuring embedded shape memory alloys

W. Zhang, M. Davis, Nikhil Koratkar

Proceedings Volume 4699, (2002) https://doi.org/10.1117/12.474997

KEYWORDS: Shape memory alloys, Composites, Absorption, Epoxies, Smart materials, Actuators, Carbon, Failure analysis, Beam shaping, Glasses

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Proceedings Article | 22 June 2000 Paper

Hover testing of a Mach-scaled rotor with piezoelectric-bender-actuated trailing-edge flaps

Nikhil Koratkar, Inderjit Chopra

Proceedings Volume 3985, (2000) https://doi.org/10.1117/12.388807

KEYWORDS: Actuators, Aerodynamics, Control systems, Ferroelectric materials, Foam, Skin, Composites, Sensors, Motion models, Wind measurement

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Proceedings Article | 27 July 1998 Paper

Analysis and testing of a Mach-scaled helicopter rotor in hover with piezoelectric bender-actuated trailing-edge flaps

Nikhil Koratkar, Inderjit Chopra

Proceedings Volume 3329, (1998) https://doi.org/10.1117/12.316900

KEYWORDS: Actuators, Aerodynamics, Ferroelectric materials, Analytical research, Skin, Control systems, Foam, Polarization, Motion models, Adhesives

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This paper presents an analytic model and validation tests of Froude and Mach scaled rotors featuring piezoelectric bender actuated trailing-edge flaps for active vibration suppression. A finite element structural formulation in conjunction with time domain unsteady aerodynamics is used to develop the rotor blade and bender-flap coupled response in hover. The analysis accounts for the aerodynamic, centrifugal, inertial and frictional loads acting on the coupled bender-flap-rotor system in hover. To investigate the feasibility of piezo-bender actuation and validate the analytic model, a 6 foot diameter, two-bladed Froude scaled rotor with piezo-bender actuation is tested on the hover stand. Flap deflections of +/- 4 to +/- 8 degrees, for 1 to 5 /rev bender excitation were achieved at the Froude scaled operating speed of 900 RPM. The trailing-edge flap activation resulted in a 10% variation in the rotor thrust levels at 6 degrees collective pitch. The analytic model shows good correlation with experimental flap deflections and oscillatory hubloads for different rotor speeds and collective settings. Based on the analytic model, two Mach scaled rotor blades with piezo-bender actuation are designed and fabricated. To achieve the desired flap performance at Mach scale, an 8-layered, tapered bender is fabricated. The bender performance is further improved by selectively applying large electric fields in the direction of polarization for individual piezoceramic elements. A radial bearing is incorporated to reduce frictional loads at the blade-flap interface. Preliminary testing of the Mach scaled blades at 900 RPM in a vacuum chamber revealed negligible degradation in flap performance because of centrifugal and frictional loading. The analysis predicts that flap deflections of +/- 5 to +/- 10 degrees for 1 to 4 /rev bender excitation can be achieved at the Mach scaled operating speed of 2100 RPM. Future work will involve hover and wind tunnel testing at Mach scaled operating speeds.

Proceedings Article | 6 June 1997 Paper

Testing and validation of a Froude-scaled helicopter rotor model with piezo-bimorph-actuated trailing edge flaps

Nikhil Koratkar, Inderjit Chopra

Proceedings Volume 3041, (1997) https://doi.org/10.1117/12.275646

KEYWORDS: Actuators, Aerodynamics, Ferroelectric materials, Control systems, Sensors, Motion models, Performance modeling, Analytical research, LabVIEW, Control systems design

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Showing 5 of 13 publications

Conference Committee Involvement (7)

Nano-, Bio-, and Info-Tech Sensors and Systems

9 March 2009 | San Diego, California, United States

Nanosensors and Microsensors for Bio-Systems

11 March 2008 | San Diego, California, United States

Nano-, Micro- and Bio-Sensors and Systems

21 March 2007 | San Diego, California, United States

Damping and Isolation

27 February 2006 | San Diego, California, United States

Smart Electronics, MEMS, BioMEMS, and Nanotechnology

27 February 2006 | San Diego, California, United States

Showing 5 of 7 Conference Committees

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