1 Introduction

This book is about human senses and movement, how they function on the nanoscale,

and how they can be mimicked on the nanoscale by technology. To understand this sub-

ject, it is necessary to first know a little about what happens in the human body and what

takes place at the nanoscale more generally. This introduction will help you by provid-

ing an overview on several topics. It will also include common measurement techniques

and an introduction to sensors. Feel free to only look at the sections you need help with;

each section should be understandable by itself. References will be provided if you want

to look into a topic in more detail.

1.1 Introduction to Cell Biology and Cell Communication

Let’s start with some basic physiology [1]. Skin, the biggest organ of the body, surrounds

and protects the other organs, each with their separate function. The skeleton holds up

all of the organs and cells, the brain coordinates reactions to our environment, plans

and regulates movement, the lungs provide oxygen so that fuel can be burnt and energy

for the body created, this fuel is collected and broken down in the stomach, but toxic

compounds and waste are secreted via the kidneys. The liver produces whatever needs

to be produced to make it all work, and the heart is responsible for the transport of

nutrients throughout the body. Why does each function have its own organ?

The short answer is that for each organ to be able to function correctly it needs its

own environment [1]. Each organ has different genes that are active and works with

different chemical compounds in its cells, using a variety of reactions to reach its goals.

And each organ, and the body itself, can only function in very controlled conditions

within a narrow margin. These narrow margins are called homeostasis. The body has

an overall homeostasis or set of requirements and conditions, but so does each organ

and each individual cell.

To maintain those conditions, membranes envelop the body, each organ, and each

cell. These border-enclosed spaces can then be controlled separately. But here is the

problem with this approach: each of those separated spaces, including each cell, must

still work together to create a functioning body. Humans have trillions and trillions of

cells, and yet humans are not just a random heap of cells. The cells organize themselves

into tissues, each tissue is ordered into organs, and each organ is combined to form a

human. Humans have a hard time organizing several people; how can the body orga-

nize trillions of cells? And not only organize the cells into a static structure, but create

an active, environment-responsive, moving and thinking human? The answer is: com-

munication, communication, communication.

Before we get to the communication part, let us look at the structure of a cell and

how it functions (Figure 1.1). The nucleus contains all information for the cell coded in

the double-stranded deoxyribonucleic acid (DNA). The sequence of four different bases

https://doi.org/10.1515/9783110779196-001