Nanoelectromechanics in Engineering and Biology

by Hughes; Michael Pycraft

• ISBN13: 9780849311833
• ISBN10: 0849311837
• Format: Hardcover
• Copyright: 2002-10-29
• Publisher: CRC Press

Summary

The success, growth, and virtually limitless applications of nanotechnology depend upon our ability to manipulate nanoscale objects, which in turn depends upon developing new insights into the interactions of electric fields, nanoparticles, and the molecules that surround them. In the first book to unite and directly address particle electrokinetics and nanotechnology, Nanoelectromechanics in Engineering and Biology provides a thorough grounding in the phenomena associated with nanoscale particle manipulation. The author delivers a wealth of application and background knowledge, from using electric fields for particle sorting in lab-on-a-chip devices to electrode fabrication, electric field simulation, and computer analysis. It also explores how electromechanics can be applied to sorting DNA molecules, examining viruses, constructing electronic devices with carbon nanotubes, and actuating nanoscale electric motors. The field of nanotechnology is inherently multidisciplinary-in its principles, in its techniques, and in its applications-and meeting its current and future challenges will require the kind of approach reflected in this book. Unmatched in its scope, Nanoelectromechanics in Engineering and Biology offers an outstanding opportunity for people in all areas of research and technology to explore the use and precise manipulation of nanoscale structures.

Author Biography

Michael Pycraft Hughes was born on Holy Island off the coast of Wales in 1970. He attended the University of Wales at Bangor for both his master of engineering (1992) and Ph.D. (1995) studies and has since worked in laboratories in the University of Glasgow (Scotland) and the M.D. Anderson Cancer Center, Houston (USA). In 1999, he was appointed lecturer in microengineering at the Centre for Biomedical Engineering, in the School of Engineering at the University of Surrey (England). He has authored or co-authored over 60 journal papers, conference papers, and book chapters. Dr. Hughes's research activities include dielectrophoresis applied to cancer biology and biosensors, laboratory-on-a-chip technology, applications of electrokinetics to nanotechnology, colloid and surface science, micro-engineered neural implants, neural signal processing, and neural computing. His teaching activities include instrumentation, sensors, artificial intelligence, biological safety, physiological measurement, and microengineering in medicine and biology

Table of Contents

Movement from electricity	p. 1
Introduction	p. 1
The promise of nanotechnology	p. 3
Electrokinetics	p. 5
Electrokinetics and nanoparticles	p. 9
A note on terminology	p. 10
References	p. 12
Electrokinetics	p. 15
The laws of electrostatics	p. 15
Coulomb's law, electric field, and electrostatic potential	p. 15
Gauss's, Laplace's, and Poisson's equations	p. 19
Conductance and capacitance	p. 21
Conductance and conductivity	p. 21
Capacitance	p. 23
Impedance	p. 25
Polarization and dispersion	p. 26
Dipoles and polarization	p. 26
Complex permittivity	p. 29
Dispersion and relaxation processes	p. 30
Debye relaxation	p. 30
The Maxwell-Wagner relaxation	p. 33
Dielectric spheres in electric fields	p. 35
Forces in field gradients: dielectrophoresis and electrorotation	p. 39
Dielectrophoresis	p. 39
Electrorotation	p. 42
Electro-orientation	p. 45
Dipole-dipole interactions: pearl chaining	p. 46
Higher order multipoles	p. 48
Supplementary reading	p. 50
Colloids and surfaces	p. 51
Colloids	p. 51
The electrical double layer	p. 51
The Gouy-Chapman model	p. 52
The Stern layer	p. 56
Particles in moving fluids	p. 59
Colloids in electric fields	p. 60
Electrode polarization and fluid flow	p. 63
Other forces affecting colloidal particles	p. 69
Viscous drag	p. 69
Buoyancy	p. 70
Brownian motion and diffusion	p. 70
Colloidal interaction forces	p. 72
References	p. 73
Supplementary reading	p. 74
Analysis and manipulation of solid particles	p. 75
Dielectrophoresis of homogeneous colloids	p. 75
Frequency-dependent behavior and the crossover frequency	p. 76
Double layer effects	p. 80
Charge movement in the double layer	p. 81
Charge movement in the Stern and diffuse double layers	p. 82
Stern layer conduction and the effects of bulk medium properties	p. 84
Dispersion in the Stern Layer	p. 86
Dielectrophoresis versus fluid flow	p. 87
Separating spheres	p. 89
Trapping single particles	p. 93
Theory of dielectrophoretic trapping	p. 94
Trapping using positive dielectrophoresis	p. 95
Trapping using negative dielectrophoresis	p. 96
Limitations on minimum particle trapping size	p. 98
Dielectrophoresis and laser trapping	p. 102
References	p. 104
Dielectrophoresis of complex bioparticles	p. 107
Manipulating viruses	p. 107
Anatomy of viruses	p. 108
The multishell model	p. 109
Methods of measuring dielectrophoretic response	p. 112
Experimental considerations	p. 112
Crossover measurements	p. 114
Collection rate measurements	p. 115
Phase analysis light scattering techniques	p. 117
Measurement of levitation height	p. 118
Particle velocity measurement	p. 120
Examining virus structure by dielectrophoresis	p. 121
The interpretation of crossover data	p. 123
Clarifying assumptions	p. 123
Interpretation of results	p. 125
The effects of storage	p. 128
Studying nonspherical particles	p. 130
Separating viruses	p. 133
Unexpected charge effects	p. 134
References	p. 136
Supplementary reading	p. 137
Dielectrophoresis, molecules, and materials	p. 139
Manipulation at the molecular scale	p. 139
Manipulating proteins	p. 139
Dielectrophores for protein analysis	p. 140
Qualitative description	p. 141
Crossover as a function of conductivity	p. 142
Crossover as a function of conductivity and pH	p. 143
DNA	p. 146
Dielectrophoretic manipulation of DNA	p. 148
Applications of DNA manipulation	p. 150
Electrical measurement of single DNA molecules	p. 150
Stretch-and-positioning of DNA	p. 151
Molecular laser surgery	p. 152
Nanotubes, nanowires, and carbon-60	p. 153
References	p. 156
Nanoengineering	p. 159
Toward molecular nanotechnology	p. 159
Directed self-assembly	p. 160
Device assembly	p. 161
Electrostatic self-assembly	p. 162
Electronics with nanotubes, nanowires, and carbon-60	p. 164
Putting it all together: the potential for dielectrophoretic nanoassembly	p. 168
Dielectrophoresis and materials science	p. 169
Deposition of coatings	p. 169
Three-dimensional material structuring	p. 170
Dewatering	p. 173
Nanoelectromechanical systems	p. 174
References	p. 175
Practical dielectrophoretic separation	p. 177
Limitations on dielectrophoretic separation	p. 177
Flow separation	p. 178
Field flow fractionation	p. 182
Thermal ratchets	p. 184
Separation strategies using dielectrophoretic ratchets	p. 189
Stacked ratcheting mechanisms	p. 191
Traveling wave dielectrophoresis	p. 193
Applications of traveling wave dielectrophoresis	p. 200
Manipulation	p. 200
Separation	p. 201
Fractionation	p. 201
Concentration	p. 202
References	p. 204
Electrode structures	p. 207
Microengineering	p. 207
Electrode fabrication techniques	p. 208
Photolithography	p. 208
Wet etching	p. 210
Dry etching	p. 215
Laser ablation	p. 216
Direct-write e-beam structures	p. 217
Multilayered planar construction	p. 218
Microfluidics	p. 219
Other fabrication techniques	p. 221
Laboratories on a chip	p. 222
Steering particles around electrode structures	p. 224
Particle detection	p. 226
Integrating electrokinetic subsystems	p. 228
Contact with the outside world	p. 230
A note about patents	p. 231
References	p. 233
Supplementary reading	p. 237
Computer applications in electromechanics	p. 239
The need for simulation	p. 239
Principles of electric field simulation	p. 239
Analytical methods	p. 240
Electrode geometries with analytical solutions to their electric fields	p. 240
Modeling time-dependent behavior using analytical methods	p. 244
Numerical methods	p. 246
The finite difference method	p. 247
The finite element method	p. 248
Boundary element methods	p. 249
The Monte Carlo method	p. 249
The method of moments	p. 250
Finite element analysis	p. 251
Local elements and the shape function	p. 251
The Galerkin method	p. 253
Quadrilateral elements	p. 256
Assembling the elements	p. 258
Applying boundary conditions	p. 259
The solution process	p. 261
The method of moments	p. 261
Calculating charge density	p. 262
Calculating the potential	p. 265
Commercial versus custom software	p. 266
Determination of dynamic field effects	p. 267
The nature of the dynamic field	p. 267
Example: simulation of polynomial electrodes	p. 269
Simulations	p. 269
Simulation results	p. 271
References	p. 275
Dielectrophoretic response modeling and MATLAB	p. 279
Modeling the dielectrophoretic response	p. 279
Programming in MATLAB	p. 280
Modeling the Clausius-Mossotti factor	p. 280
Determining the crossover spectrum	p. 283
Modeling surface conductance effects	p. 288
Multishell objects	p. 290
Finding the best fit	p. 292
MATLAB in time-variant field analysis	p. 293
Other MATLAB functions	p. 296
A dielectrophoretic rotary nanomotor: a proposal	p. 297
Electrokinetic nanoelectromechanical systems	p. 297
Calculation of motor performance	p. 298
Theoretical limits of motor performance	p. 302
Digital electronic control of torque generation	p. 306
Nanomotor applications	p. 308
The way forward?	p. 310
References	p. 311
Index	p. 313
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