Mechanical Engineering
220 S. W. Mudd, MC 4703,
212-854-2965
www.columbia.edu/cu/mechanical
Mechanical engineering is a diverse subject that derives its breadth from the
need to design and manufacture everything from small individual parts/devices (e.g.,
micro-scale sensors, inkjet printer nozzles) to large systems (e.g., spacecraft and
machine tools). The role of a mechanical engineer is to take a product from an idea to
the marketplace. In order to accomplish this, a broad range of skills are needed. The
particular skills in which the mechanical engineer acquires deeper knowledge are the
ability to understand the forces and the thermal environment that a product, its parts,
or its subsystems will encounter; design them for functionality, aesthetics, and the
ability to withstand the forces and the thermal environment they will be subjected to;
determine the best way to manufacture them and ensure they will operate without failure.
Perhaps the one skill that is the mechanical engineer’s exclusive domain is the ability
to analyze and design objects and systems with motion.
Since these skills are required
for virtually everything that is made, mechanical engineering is perhaps the broadest
and most diverse of engineering disciplines. Hence mechanical engineers play a central
role in such industries as automotive (from the car chassis to its every
subsystem—engine, transmission, sensors); aerospace (airplanes, aircraft engines,
control systems for airplanes and spacecraft); biotechnology (implants, prosthetic
devices, fluidic systems for pharmaceutical industries); computers and electronics (disk
drives, printers, cooling systems, semiconductor tools); microelectromechanical systems,
or MEMS (sensors, actuators, micro power generation); energy conversion (gas turbines,
wind turbines, solar energy, fuel cells); environmental control (HVAC, air-conditioning,
refrigeration, compressors); automation (robots, data/image acquisition, recognition,
and control); manufacturing (machining, machine tools, prototyping, microfabrication).
To put it simply, mechanical
engineering deals with anything that moves, including the human body, a very complex
machine. Mechanical engineers learn about materials, solid and fluid mechanics,
thermodynamics, heat transfer, control, instrumentation, design, and manufacturing to
realize/ understand mechanical systems. Specialized mechanical engineering subjects
include biomechanics, cartilage tissue engineering, energy conversion, laser-assisted
materials processing, combustion, MEMS, microfluidic devices, fracture mechanics,
nanomechanics, mechanisms, micro-power generation, tribology (friction and wear), and
vibrations. The American Society of Mechanical Engineers (ASME) currently lists
thirty-six technical divisions, from advanced energy systems and aerospace engineering
to solid waste engineering and textile engineering.
The breadth of the mechanical
engineering discipline allows students a variety of career options beyond some of the
industries listed above. Regardless of the particular future path they envision for
themselves after they graduate, their education would have provided them with the
creative thinking that allows them to design an exciting product or system, the
analytical tools to achieve their design goals, the ability to meet several sometimes
conflicting constraints, and the teamwork needed to design, market, and produce a
system. These skills also prove to be valuable in other endeavors and can launch a
career in medicine, law, consulting, management, banking, finance, and so on.
For those interested in applied
scientific and mathematical aspects of the discipline, graduate study in mechanical
engineering can lead to a career of research and teaching.
Current Research Activities
Current research activities in
the Department of Mechanical Engineering are in the areas of controls and robotics,
energy and micropower generation, fluid mechanics, heat/mass transfer, mechanics of
materials, manufacturing, material processing, MEMS, nanotechnology, and orthopedic
biomechanics.
Biomechanics and Mechanics of Materials.
Some of the current research in
biomechanics is concerned with the application of continuum theories of mixtures to
problems of electromechanical behavior of soft biological tissues, contact mechanics,
lubrication of diarthrodial joints, and cartilage tissue engineering. (Ateshian)
In the area of the mechanics of
materials, research is performed to better understand material constitutive behavior at
the micro- and mesolength scales. This work is experimental, theoretical, and
computational in nature. The ultimate goal is to formulate constitutive relationships
that are based on physical concepts rather than phenomenology, as in the case of
plasticity power-law hardening. In addition, the role that the constitutive relations
play in the fracture and failure of materials is emphasized. (Kysar)
Control,
Design, and Manufacturing.
Control research
emphasizes iterative learning control (ILC) and repetitive control (RC). ILC creates
controllers that learn from previous experience performing a specific command, such as
robots on an assembly line, aiming for high-precision mechanical motions. RC learns to
cancel repetitive disturbances, such as precision motion through gearing, machining,
satellite precision pointing, particle accelerators, etc. Time optimal control of robots
is being studied for increased productivity on assembly lines through dynamic motion
planning. Research is also being conducted on improved system identification, making
mathematical models from input-output data. The results can be the starting point for
designing controllers, but they are also studied as a means of assessing damage in civil
engineering structures from earthquake data. (Longman)
Robotics and mechanism synthesis
research focuses on the analysis of kinematic relationship, optimization, and design of
linkages and spatial mechanisms, and the development of novel robotic mechanical
architectures. These new robotic architectures include parallel robots, hybrid robots,
snakelike robots, and flexible and flexure-based robots. The theoretical aspects of this
research include applications of line geometry tools and screw theory for analysis and
synthesis of robotic devices, applications of actuation redundancy and kinematic
redundancy for stiffness control, and applications of algebraic geometry methods for
robot synthesis. The applied aspects of this research include task-based design and
construction of new devices/robots for robotic medical assistance in the surgical arena.
(Simaan)
In the area of advanced
manufacturing processes and systems, current research concentrates on laser materials
processing. Investigations are being carried out in laser micromachining; laser forming
of sheet metal; microscale laser shock-peening, material processing using improved
laser-beam quality. Both numerical and experimental work is conducted using
state-of-the-art equipment, instruments, and computing facilities. Close ties with
industry have been established for collaborative efforts. (Yao)
Energy,
Fluid Mechanics, and Heat/Mass Transfer.
In the area of energy, one effort
addresses the design of flow/mass transport systems for the extraction of carbon dioxide
from air. Another effort addresses the development of distributed sensors for use in
micrositing and performance evaluation of energy and environmental systems. The design
and testing of components and systems for micropower generation is part of the
thermofluids effort as well as part of the MEMS effort. (Modi)
In the area of fluid mechanics,
study of low-Reynolds-number chaotic flows is being conducted both experimentally and
numerically, and the interactions with molecular diffusion and inertia are presently
being investigated. Other areas of investigation include the fluid mechanics of inkjet
printing, drop on demand, the suppression of satellite droplets, shock wave propagation,
and remediation in high-frequency printing systems. (Attinger, Modi)
In the area of microscale
transport phenomena, current research is focused on understanding the transport through
interfaces, as well as the dynamics of interfaces. For instance, an oscillating
microbubble creates a microflow pattern able to attract biological cells. High-speed
visualization is used together with innovative laser measurement techniques to measure
the fluid flow and temperature field with a very high resolution. (Attinger).
MEMS and
Nanotechnology.
In these areas, research
activities focus on power generation systems, nanostructures for photonics, fuel cells
and photovoltaics, and microfabricated adaptive cooling skin and sensors for flow,
shear, and wind speed. Basic research in fluid dynamics and heat/mass transfer phenomena
at small scales also support these activities. (Attinger, Hone, Lin, Modi, Wong)
Research in the area of
nanotechnology focuses on nanomaterials such as nanotubes and nanowires and their
applications, especially in nanoelectromechanical systems (NEMS). A laboratory is
available for the synthesis of carbon nanotubes and semiconductor nanowires using
chemical vapor deposition (CVD) techniques and to build devices using electron-beam
lithography and various etching techniques. This effort will seek to optimize the
fabrication, readout, and sensitivity of these devices for numerous applications, such
as sensitive detection of mass, charge, and magnetic resonance. (Hone, Wong, Modi)
Research in the area of optical
nanotechnology focuses on devices smaller than the wavelength of light, for example, in
photonic crystal nanomaterials and NEMS devices. A strong research group with facilities
in optical (including ultrafast) characterization, device nanofabrication, and full
numerical intensive simulations is available. Current efforts include silicon
nanophotonics, quantum dot interactions, negative refraction, dramatically enhanced
nonlinearities, and integrated optics. This effort seeks to advance our understanding of
nanoscale optical physics, enabled now by our ability to manufacture, design, and
engineer precise subwavelength nanostructures, with derived applications in
high-sensitivity sensors, high-bandwidth data communications, and biomolecular sciences.
Major ongoing collaborations across national laboratories, industrial research centers,
and multiuniversities support this research. (Wong)
In the area of microscale power
generation, efforts are dedicated to build a micromotor using acoustic energy amplified
by a microbubble. (Attinger)
Research in BioMEMS aims to design
and create MEMS and micro/nanofluidic systems to control the motion and measure the
dynamic behavior of biomolecules in solution. Current efforts involve modeling and
understanding the physics of micro/ nanofluidic devices and systems, exploiting polymer
structures to enable micro/nanofluidic manipulation, and integrating MEMS sensors with
microfluidics for measuring physical properties of biomolecules. (Lin)
Facilities for Teaching and Research
The undergraduate laboratories,
occupying an area of approximately 6,000 square feet of floor space, are the site of
experiments ranging in complexity from basic instrumentation and fundamental exercises
to advanced experiments in such diverse areas as automatic controls, heat transfer,
fluid mechanics, stress analysis, vibrations, microcomputer-based data acquisition, and
control of mechanical systems.
Equipment includes microcomputers
and microprocessors, analog-to-digital and digital-to-analog converters, lasers and
optics for holography and interferometry, a laser-Doppler velocimetry system, a
Schlieren system, dynamic strain indicators, a servohydraulic material testing machine,
a photoelastic testing machine, an internal combustion engine, a dynamometer, subsonic
and supersonic wind tunnels, a cryogenic apparatus, computer numerically controlled
vertical machine centers (VMC), a coordinate measurement machine (CMM), and a rapid
prototyping system. A CNC wire electrical discharge machine (EDM) is also available for
the use of specialized projects for students with prior arrangement. The undergraduate
laboratory also houses experimental setups for the understanding and performance
evaluation of a complete small steam power generation system, a heat exchanger, and a
compressor. Part of the undergraduate laboratory is a staffed machine shop with
machining tools such as standard vertical milling machines, engine and bench lathes,
programmable surface grinder, bandsaw, drill press, tool grinders, and a power hacksaw.
The shop also has a tig welder.
A mechatronics laboratory affords
the opportunity for hands-on experience with microcomputer-embedded control of
electromechanical systems. Facilities for the construction and testing of analog and
digital electronic circuits aid the students in learning the basic components of the
microcomputer architecture. The laboratory is divided into work centers for two-person
student laboratory teams. Each work center is equipped with several power supplies (for
low-power electronics and higher power control), a function generator, a multimeter, a
protoboard for building circuits, a microcomputer circuit board (which includes the
microcomputer and peripheral components), a microcomputer programmer, and a personal
computer that contains a data acquisition board. The data acquisition system serves as
an oscilloscope, additional function generator, and spectrum analyzer for the student
team. The computer also contains a complete microcomputer software development system,
including editor, assembler, simulator, debugger, and C compiler. The laboratory is also
equipped with a portable oscilloscope, an EPROM eraser (to erase microcomputer programs
from the erasable chips), a logic probe, and an analog filter bank that the student
teams share, as well as a stock of analog and digital electronic components.
The department maintains a modern
computer-aided design laboratory equipped with fifteen Silicon Graphics workstations and
software tools for design, CAD, FEM, and CFD.
The research facilities are
located within individual or group research laboratories in the department, and these
facilities are being continually upgraded. To view the current research capabilities
please visit the various laboratories within the research section of the department website.
The students and staff of the department can, by prior arrangement, use much of the equipment in these research facilities. Through their participation in the NSF-MRSEC center, the faculty also have access to shared instrumentation and the clean room located in the Shapiro Center for Engineering and Physical Science Research. Columbia University’s extensive library system has superb scientific and technical collections. E-mail and computing services are maintained by Columbia University Information Technology (CUIT).