Chapter 1 Introduction

1.1 Introduction to NMR

Nuclear Magnetic Resonance (NMR) has evolved from a probe of the nuclear spin to a tool that can detect cancerous cell. The nucleus - like the electrons - has a magnetic moment that arises from its isospin. Both the neutron and the proton have half integer spin, however, due to its larger mass, the magnetic moment is significantly smaller. Given a polarizing magnetic field, a secondary perpendicular magnetic field can apply a torque to the spin of the nucleus. The frequency or energy is characteristic to the nucleus and magnitude of the applied field, which splits the up and down spin’s energy levels. It is also referred to as the Larmor frequency.

The precession would continue forever, if it were not for spin-lattice or spin-spin interactions. The characteristic time of the precession decay is referred to as \(T_1\) or \(T_2\) constants. These can be measured using either a free induction decay signal or a pulse sequence that generates subsequent spin echoes.

1.2 Introduction to AFM

Scanning Probe Microscopy (SPM) epitomizes nanotechnology as it can resolve details at a level beyond the optical limits. SPM is a collective term for many techniques that have born out, such as atomic force microscopy (AFM). Its advantage is that it can be broadly applied to insulating and conducting samples and measures the surface forces.

While some things are visible under the optical microscope, such as hair, bacteria, cells, and even mitochondria, others are smaller than the wavelength of optical light. This includes viruses, DNA, quantum dots, nanoparticles, small molecules, and atoms.

Nanotechnology is one of the most promising technologies of the 21st century. It is the ability to convert the nanoscience theory to useful applications by observing, measuring, manipulating, assembling, controlling and manufacturing matter at the nanometer scale.

There is plenty of room at the bottom. – Richard Feynman

1.3 Introduction to Prototyping with Arduino

The Arduino microcontroller serves as an experimental tool to prototype new electornic devices. It is licensed under GNU Lesser General Public License (LGPL). The microcontroller can be programmed to execute a particular set of instructions. It allows the interaction of sensors with the environment and can output data LEDs or transfer directly to a computer via USB or WiFi.

Creating new electronics often requires error and trial and so the Arduino microcontroller provides a useful tool to prototype. Together with a 3D printer, useful novel applications can be built.