Chapter 9: Scaling, Actuators, and Power in Miniaturized Systems

Introduction

Scaling

Introduction

Micro Intuition and Nature as a Guide

Micro Intuition

Nature as a Guide

Scaling of Length, Surface Area, and Volume

Scaling in Flying and Swimming

Scaling and Surface Tension

Scaling and Diffusion

Scaling of Minimal Analytical Sample Size

Scaling in Electrochemistry

Scaling in Optics

Scaling of Strength-to-Weight Ratio and Inertia

Fundamental Frequency and Quality Factor

Fundamental Frequency

Quality Factor

Muscle, Flagellum, and Protein Motors

Trimmer’s Vertical Bracket Notation

Actuators

Introduction

Electric Actuators

Electrostatics

Continuum Theory

Breakdown of Continuum Theory for Electrostatics

Piezoelectricity

Introduction

Mechanism of Piezoelectricity

Piezoelectric Applications

Overview

Piezoelectric Motors

Piezoelectric Pumping/ Piezopumps

Chemical Acoustic Sensing

Mechanical Acoustic Sensing

Piezoelectric Materials

Dielectric Induction

Electrostriction

Pyroelectricity

Thermoelectricity

Electrets

Electrorheological Fluids

DC Electrokinetic Effects

Introduction to Electrophoresis and Electro-Osmosis

Electrophoresis

Electro-osmosis

Flow Profiles

Electrowetting

Fluidic Networks

Optimum Size of Fluidic Channels-Scaling

Open Electrophoresis

Capillary Isoelectric Focusing

AC Electrokinetic Effects

Introduction

Dielectrophoresis Force

Traveling Wave Dielectrophoresis

Particle Levitation

Electrorotation

Scaling Considerations

Applications

Magnetic Actuators

Introduction

Scaling in Magnetics

Magnetic Levitation

Introduction

Levitation with Permanent and Electromagnets

Diamagnetism

Levitation with Superconductors

Magnetohydrodynamic Pumping

Magnetostriction

Comparing Magnetic with Electrostatic Actuation

Introduction

Micro Motors

Conclusions on Electrostatics versus Electromagnetics

Fluidics

Introduction

Macroscale Laws for Fluid Flow

Definition of Fluids

Stokes-Navier Equations

Introduction

Hagen-Poiseuille Law

Reynolds Number and Friction Factor

Hydrodynamic Boundary Layer

Breakdown of Flow Continuum

Capillary Forces

Introduction

Capillary Forces

Passive Valving in Pump Driven Systems

Passive Valves on a Centrifugal Platform

Thermal Actuators

Introduction

Macroscale Laws in Heat Conduction

Fourier Law of Heat Conduction

Newton’s Cooling Law

Radiation

Biot's Number

Thermal Boundary Layer Thickness

Breakdown of Continuum in Heat Transfer

Example Thermal Actuators

Thermopneumatic Actuators

TABLE 9.11 Comparison of Micromachined Thermal Valves

Bimetallic Actuators

Shape Memory Alloy Actuators

Scaling in Analytical Separation Equipment

Introduction

Commonly Used Terms in Separation Chemistry

Band Broadening in the Column

Other Band-Broadening Effects

Scaling

Other Actuators

Power in MEMS

Introduction

MEMS Batteries and Capacitors

Beam Energy to the MEMS

Heat Powered MEMS

Kinetic Energy Driven MEMS

Combustion Engines in MEMS

Examples

9. 1 The Bead Array Counter (BARC)

9.2 The Nanogen Chip

9.3 Field Ionization Sources

Problems