Case-lesson "Smartphone means everything to me"

Category: Science, Nature and human

Level (grade): 7-8

Subject: Applied science

Objective: To systematize multi-vector knowledge which is used in the design of mobile phones.

What information is waiting for me here?
  • How do mobile phones work?
  • Why is it called a cellular mobile communication?
  • Why do some airlines ask passengers to turn off their cell phones?
  • How are physics and chemistry involved in the design of the phone?
  • What type of fundamental and practical knowledge will be useful for me?
4 scans of the subjects, phenomena and practices:

Today, a smartphone is a gadget that no modern man can do without in the world based on technologies.

The smartphone has many useful and interesting features. Some of them we use on a daily basis, while others can be used not so often.

When we look at this small device it is hard to imagine how it can contain hundreds of different gigabytes of data!

Being a part of our life the smartphones highlight technological progress and innovations. The latest discoveries and breakthroughs are implemented in our gadgets. At the same time, users' demands and expectations push scientists and inventors to constantly search for new solutions and opportunities.

Which problem is the most crucial for millions of people in using smartphones? One can say that this is a battery, quickly recharged and long lasting.

Can you imagine a battery that recharges in 30 seconds? The scientists from Seoul's Energy High School in South Korea have something to show you then! They have created an accumulator which can be recharged in less than a minute.

There is another amazing invention of the scientists from the Massachusetts Institute of Technology. They know how to generate electricity from the air using a temperature difference!

Although, the size of the new device does not fit the smartphone yet. But it is a matter of time and further work of scientists, engineers and inventors.

And, what do you think of this opportunity to recharge your smartphone in a few seconds or to do it even from air?


Your mobile phone is based primarily on the radio. Principles of radio communications are the following. The variable high frequency electric current, which is created in the antenna transmitter, causes the space around the antenna to produce high frequency electromagnetic waves. When the waves reach the receiver antenna, they induce in it an alternating current of the same frequency at which the transmitter operates.

To deliver high sound vibrations, they alter or modulate the electrical oscillations using low frequency (audio frequency). This method is called amplitude modulation.

At the receiver, modulated high frequency vibrations produce low-frequency vibrations. This conversion process is called signal detection. The resulting detection signal corresponds to the audio signal, acting on microphone transmitters.

Which means, we have the string "sound vibrations - electromagnetic waves - sound waves."

The main elements of the network are handsets and base stations. The antenna base station is divided into several sectors, each of which it has directed at its side.

Mobile telephony is a type of modern mobile radio. Its peculiarity is that the entire coverage area is divided by the coverage of individual base stations (BSS). In a perfect flat surface without buildings covering from one station in a circle. But these overlapping circles have formed hexagons - cells. That's why mobile phones are also called cellular.

We do not even notice the work which our mobile is "busy" with when we use it or leave it idle. When switched on, the phone listening airwaves are seeking the alarm base station. Finding the station, the phone sends a unique identification code to it. The station and the phone constantly communicate. Communication can be both digital and analog. The range of such station is 35 km. The phone can measure the signal strength from 32 stations simultaneously, switching to those from which the signal is stronger.

Operators have agreed among themselves, a subscriber out of range of your network can switch to another. So, this is how roaming works.

Mobile (cell) phones work by electromagnetic waves. Electromagnetic wave propagation is the process of electromagnetic interaction in space as variables connect by electric and magnetic fields. Its most important characteristics are the frequency and length. Frequency characterizes not only separate channels, but the entire network. The wave vibrations propagating through space point towards an "advancement" wave: the same point in space, moving, creating a wave. This movement in physics is called forced oscillations.

An important feature of the network is the frequency and wave vector.

Depending on the frequency, the electromagnetic waves belong to one of the spectral ranges.

Waves in various different bands interact with physical bodies. Waves with the greatest frequency are radioactive radiation with a frequency of up to tens of nanometers. Waves used for radiography, with a length of hundreds of nanometers - are ultraviolet radiation. Visible light falls in the range of 400 to 700 nm.

Millimeter and centimeter ranges - are infrared waves. The longer wavelength belongs to radio waves.

Consequently, electromagnetic waves with the lowest frequency (or the largest wavelength) belong to the radio. Radio waves transmit signals on distance via radio, television, and mobile phones. The radar works in front of the radio. The radio is divided into meter, decimeter, centimeter, or millimeter depending on the length of the electromagnetic waves.

Why do some airlines ask passengers to turn off the phones during take-off and landing?

There is a probability, although extremely small, that the frequency of the phone and appliances of the plane interfere with one another.

In fact, in modern airplanes devices work on other frequencies. Therefore, not all airlines impose such a requirement on passengers.

For, an aircraft operating frequency range is 90-150 Hz, including the piloting purposes of the navigation devices. Some airport’s device operating frequencies are in the 329-335 MHz frequency range. The frequency is the same number of standard GSM 1-2 GHz with standard UMTS 2-4 GHz. For, a 3G frequency is about 2 GHz.

Also, all mobile phones have an airplane mode. Airplane mode is a setting that allows you to quickly turn off all wireless communication means. By means of wireless communication includes Wi Fi, mobile broadband, Bluetooth, GPS or GNSS, at a short distance radio communication (NFC) and more.

Are smartphones afraid of the sun?

Another type of physical phenomena, which is associated with your mobile phone is light. First of all, it is about the screens of our phones. Most modern phones have touch screens. The development of sensor technology is in two directions: resistive sensors (that you can manage any objects) and capacitive sensors (those that react only to objects that conduct electricity). The latter lets you control some areas of the screen simultaneously - this is called the multitouch.

The capacitive touch screen is a glass panel covered with a transparent resistive material (commonly created with the alloy of indium oxide and tin oxide). The electrodes are located on the corners of the screen, a small AC voltage is served on the conductive layer (equal for all corners). When you touch the screen with your finger or other leading object a leakage current appears.

Thus, the closer the finger is to the electrode, the lesser is the resistance of the screen. This means that the current strength is greater. The current in all four corners of registered sensors, and transmitted to the controller, calculates the coordinates of the point of contact.

But such capacitive technology is a significant drawback - it is a complicated control in cold. Resistive technology does not have this disadvantage.

The sun rays affect the screen: the higher brightness it allows of the screen, the easier it is to read information on a sunny day.

Light falls on the screen (the surface) at a certain angle. Part of this light is absorbed, some is reflected. The percentage of absorbed (or reflected radiation) will depend on the color of the surface. That is, each pixel of the screen will reflect and absorb light in its own proportions depending on the color.

Thus, for the user, this phone screen illumination is important.

Illumination is a physical quantity equal to the luminous flux that falls on the illuminated surface unit ("lux" is its unit of measurement):

E=F/S, Where F - luminous flux; S - area that is illuminated (in square meters).

That is, if my phone screen area is 0.008 square meters, then it will be under different conditions fall a luminous flux:

That is, if my phone screen area is 0,008 square meters, then it will be under different conditions fall a luminous flux:

So not only is the brightness of the screen important, but the illumination while using it.



What is the illumination of the screen of your phone at this present moment? What will it be at night?


Why is my phone running out so fast? Which phone is "durable"? Can chemistry help to find a "long-lasting" battery?

Yes, because the main principle of the battery is receiving electrical current by chemical reactions. And for what elements of the periodic system will be used depends on the length of battery "life" to discharge.

Important parameters for assessing batteries are:

• High electrical density;

• The number of cycles "charge - discharge";

• Optimal size.

Types of batteries which are used in mobile phones (lithium is the most widespread among them):

Lithium-ion batteries have a high electric density and a large number of cycles "charge-discharge". This battery consists of electrodes (anode and cathode) separated by a porous separator that is made of permeated electrolytes: Packet electrodes placed in a sealed enclosure.

Another type of battery is Torah. This is a new generation of rechargeable batteries, which now "takes a step" from research laboratories to real life.

Thorium (Th) is a metal with weak radioactivity. It does not bring damage to life and health (an exception is getting directly into the blood). It is not included in biospheric processes as a factor which is not harmful to the environment. Thorium is used for concept cars (representational new generation of car models) and Innovation "advanced" battery models (including mobile phones).

Future thorium battery depends on how they are in operation soon.

Nickel-cadmium has little energy comparatively to its size. These batteries are found only in old phones.

Lithium-polymer batteries are the most technological. They have a minimum thickness used for ultra-thin phones. Also, these batteries are installed in electric vehicles.

In general, the electrochemical reactions occurring in the battery can be represented as follows. Imagine a metal plate that is immersed in water. Under the influence of polar water molecules metal ions detached from the plate and hydration passes into the liquid phase. The liquid phase thus receives a positive charge, and the metal plate has an excess of electrons. The longer the process is, the greater the charge for both the plate and liquid phase. Will have the process on the scheme:

In the summer, for example, the reaction scheme will look like:

If the environment changes, the balance moves (principle of Le Chatelier). Instead of water it is replaced with a solution of salts or special gel or special porous materials - membranes can be used. They have a selective ability – they pass only ions that we need for the battery. In brief, the external current electrochemical process will have two parts: the first is on the anode, the second is on the cathode.

At the cathode, metal ions are reduced to melt into a solid (metallic form):

For lithium cathode this process passes:

At the anode further oxidation of metal ions happens:

Given the possible degree of oxidation for Li (1), this process will go simply by increasing the amount of oxidized ions.

Most modern battery operations can be reduced to these basic chemical processes.

Why does a phone run out?

For this we use the explanation by Daniel Abraham, a scientist from Arahonnsk National Laboratory, which investigates lithium-ion batteries. He draws an analogy between the battery and a bucket with water. Charge is filling buckets. The extent of the bucket is the battery capacity, the speed in which it can fill is its power. But time, the effect of temperature and other factors form a "hole" in the bucket. By analogy with a bucket - "water leaks."

Lithium ions are removed, link. They lose the ability to move between the electrodes. Over time, the number of bound ions are increasing. The phone that needed to be charged every few days, began to need charging each day. After some amount of time the ion battery will not contain any useful charge - "bucket stops to hold water."

Why is heat harmful to my phone? When the temperature of electrolytes decompose faster, and the rate of adverse reactions, which bind lithium, is also increasing. So the battery is discharged faster, and another cycle of "charge-discharge" can be removed from the life of the phone.



Find out what type of battery your phone and the phones of your parents or friends have. Follow how often they need charging. Consider how this can be explained?

Artificial Intelligence

Mobile phones have artificial intelligence. A mobile phone (the operating system) is able to make decisions, program or application "hung" and it should be close by to offer contextual advertising ...

Examples of artificial intelligence - Android and iOS. Both operating systems have the following features of Artificial Intelligence:

1) The ability to choose and make the best decisions on the basis of earlier experiences and analysis of external influences (no reliance on intelligence activities).

2) The most important difference between genuine software artificial intelligence of simple applications is the ability to "think" with images. (With imaginative thinking today the following became available: technologies such as compression and coding of information, processing of biometric images to optimize color gamut, like research, analysis of the meaning of images, automatic cataloging information, and recognition algorithms and classification of images.)

Artificial Intelligence - promising area of technological development.

For example, Google plans to create artificial intelligence that would allow to improve sorting information to search requests. Such development should be complete by 2029. The result should be an intelligent search engine that has emotional intelligence. It has to understand human emotions.

The Japanese National Institute of Information develops an artificial intelligence system, called Todai Robot. It must seize this achievement level, that in 2021 it will successfully pass the entrance exams in the leading universities of the country.



Explore what signs of artificial intelligence does your phone have?


Before a new model of mobile phone is even on sale, it is already in high demand. Mobile phones become unfashionable, even without being technically obsolete. Importantly, a phone is a "Status" attribute, reflecting all changes of life.

Successful advertising campaigns encourage fashionistas to "upgrade" the phone to the long-awaited news. Even in spite of their price that "animates" the market of consumer loans, many people want a new phone now, and pay for it "sometimes and gradually."

For example queue for iPhone 6S lined up 4 days before the start of sales:

The queue for the iPhone 6S in Germany

Advertising companies are promoting not only the phone itself, but also related products (mobile accessories): headsets, headphones, blankets or chains, for example. In this case, designers offer a huge scope for creativity: successful decision, trendy finishes, using the popular image and we have “ideal" trendy goods. In this case the appeal is reinforced: fashion phone in a cover from a reputable manufacturer of a fashionable image. Some advertising campaigns oriented to specific categories of customers: women, girls, teenagers, etc.

Modern phone-bracelet.

The fluidity of fashion contributes to driving technology to development. But it is important not to make a sensible approach to fashion: buying something new for only status and not for opportunities, is not a good life position.

Although for many people the question of status is also very important, as they pay attention to brands. Technology allows brand promotion to become such a commodity that is easily learned. This allows people, in turn, to receive additional income from the so-called "intangible assets", which include trademarks, brands, and patents. As a result: the brand product has advantages for both producer and consumer.

Such goods like cars, watches and smartphones, are called threevector as they meet just three consumer needs. For example, the car can be seen as a convenient vehicle, a professional agent and a subject of prestige.

The same situation is with the clock: It can be beautiful; and, by simply showing the time may be an indicator of the status of the owner. Concepts of cars and smartphones with a flexible transparent screen.

Smartphones that also perform the minimum number of required user functions, can be an indicator of a "modernity" user, and may be the subject of prestige.

On the one hand, the ratios of the third vector (a measure of prestige) in a society are predominantly negative. But on the other hand, the third vector indicates the prospects of development of new technologies and consumer qualities of goods.



Make your own version of a fashion phone for girls and for boys.


The End