You’ll learn:
How the colours that light up your phone screen display work with the help of polarisation, electricity and liquid crystals.
The way the screen senses touch using light transparent conductive coatings.
How a neodymium magnet makes your phone vibrate.
What the lenses in your camera are made of and how this focuses light onto a light sensitive detector.

Prefer to skip through?
0:00-03:50 – Introduction
03:50-06:50 – What is a phone made of? > 38 common and uncommon elements that are used to make a mobile phone on the periodic table.
06:50-11:50 – The screen. Optical microscopy of the pixels in white light and individual colours.
11:50-14:30 – Shuttering and how the pixels work. Polarisation of light.
14:30-21:50 – Liquid crystals. Optical microscopy of crystals in between crossed polars, a liquid crystal molecule.
21:50-27:40 – Putting it all together in your phone screen. Sandwich construction from bottom up = light source, polariser, liquid crystal, crossed polariser. Effect of electricity on liquid crystal in pixels and how that affects light.
27:40-28:30 – Polarising sunglasses. Stop you seeing a screen well because of polarising lenses.
28:30-35:25 – Touch sensitive screen. Capacitive touch sensitivity / detectors in optically transparent yet conductive indium tin oxide.
35:25-40:20 – Vibration alert motor. Neodymium electromagnet and some coils of wire. Applying current makes a magnetic field that spins the part of the device that contains the coils, making the vibration.
40:20-41:50 – Phone camera. Lens system contains a coil of copper wire and neodymium magnets to focus light on the CMOS (complementary metal-oxide semiconductor) light sensitive detector.
41:05-48:08 – Wrapping up, thank yous and Q & A.

Glossary
Polarisation – light waves are passed through parallel slots in a grating to only let light waves with one direction pass through.
Liquid crystal – molecules that have sections that are rigid and can form ordered crystals and sections that are flexible so they can behave like liquids.
Capacitance – touching a conductive material changes how much electric charge that material can hold. Our mobile phone detects these changes to detect when and where we touch the screen.
Neodymium magnet – a strong electromagnet that is really quick to switch on and off, but relies on a rare element (neodymium).