The singer Madonna had a worldwide hit record in the 1980s (‘Material Girl’) in which she described herself as ‘the material girl living in a material world’. This is a prescient phrase for the world of today some 30 years after the release of this record. Although Madonna may have been referring to wealth and ‘cold hard cash’ in her song, the rapid development of goods for professional and consumer use really do put us at the mercy of all things material.
Today, there is frequent reference in the media to Kevlar, a polymer (i.e. a plastic) used in lightweight protective bullet-proof body armour. The impetus for developing Kevlar in the early 1960s was as a lightweight replacement for steel cords used to reinforce automobile tyres. The inventor, Stephanie Kwolek, was an American chemist and inventor or co-inventor of 17 granted US patents, an admirable role model for any younger person interested in pursuing a career in STEM subjects. Kevlar is a polymer that can be spun from solution into continuous fibres that can then be woven into fabrics. Although Kevlar is a very different material to candy floss, there are analogies in the manufacturing process for their production because both are produced by spinning molten liquid quickly through a spinning disc (spinerette) that contains holes to create a superfine material.
Another polymer system attracting much attention nowadays involves polymer banknotes, for example the five pound sterling note issued by the Bank of England in September 2016. Although widely used in everyday life, the problem of recycling plastics is a pressing issue for protection of the environment. The desire to protect the environment and to reduce the requirement to manufacture plastics from petrochemical sources (i.e. oil) is leading to research on the production of biodegradable plastics and plastics from renewable sources. Polylactic acid is a biodegradable plastic that has medical applications, for example as sutures (i.e. stitches).
The Material Girl from the 1980s will be amazed at the vast range of consumer goods available today, particularly electronic devices such as mobile phones, laptop computers, and tablet computers. Why is this? People walking along the street immersed in looking at their mobile phone screens oblivious of the surrounding environment, making phone calls, downloading music, and monitoring social media are scenes unknown to people in the 1980s. Large-screen televisions, some of which can be wall-hung may be compared with bulkier models from previous decades. The miniaturisation of consumer goods has been driven by the availability of materials with novel properties. Thus liquid crystals, light-emitting diodes (LEDs), quantum dot, and organic light-emitting diodes (OLEDs) are critical for clearer and sharper displays. Exploitation of materials can take a very long time. The phenomenon of electroluminescence that underpins the physical processes involved in LEDs was first observed in the early 20th century by Henry Round but commercial exploitation of LEDs – and wide use of the acronym – has only taken off in recent years.
The ability to pack more and more transistors onto silicon chips by photolithography whereby the number of transistors approximately follows Moore’s Law contributes to the increasing computer power of electronic devices. Whether quantum computers replace conventional digital computers in the 21st century remains to be seen, but if this happens then they may lead to easier methods for breaking encryption codes that are currently used, for example, in internet banking. If such codes are broken then internet banking in its present form would be less secure.
Advances in materials have also been instrumental in the development of medical diagnostics since the 1970s. For example magnetic resonance imaging (MRI) is taken for granted nowadays as a routine technique. Interestingly, MRI has its origins in the technique of nuclear magnetic resonance (NMR) used in structure determination in chemistry but for branding purposes the word nuclear is avoided when discussing MRI with the general public. The term ‘nuclear magnetic resonance’ was first used by the physicists E M Purcell and F Bloch in the 1940s. Paul Lauterbur showed, in the early 1970s, how to make two-dimensional images of the body with magnetic resonance by using gradients in the external magnetic field. Sir Peter Mansfield developed the technique further and derived mathematical methods for quickly deciphering the radio signals and turning them into three-dimensional images. Lauterbur and Mansfield were awarded the Noble Prize for Physiology or Medicine in 2003. MRI depends on the generation of strong magnetic fields using superconducting metallic alloys immersed in liquid helium. There is now potential for using high-temperature ceramic superconductors which have economic benefits since liquid nitrogen can replace liquid helium as a cheaper alternative. This example shows the importance of materials in the development of diagnostic techniques.
One area of pharmaceuticals that offers hope for treatment of currently-incurable diseases involves use of biologic drugs, developed throughout the 1990s. These are proteins known as monoclonal antibodies. They have high molecular weights in the tens of thousands compared to several hundred for conventional pharmaceutical compounds and have a larger molecular size. An example of a monoclonal antibody is Herceptin for the treatment of breast cancer where it binds to a protein that is present in excess in this condition.
If the Material Girl of the 1980s surveyed the world today, she would undoubtedly find herself living in a much more advanced material world.
Featured image credit: LED screen wall by Photonic Syntropy. CC BY 2.0 via Flickr.