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Taken at its face value, the term “quantum polymers” may seem somewhat oxymoronic: “quantum” means the smallest possible size of something; “polymer” means a large molecule, or macromolecule, made up of many repeating subunits.
However, in the relatively new field of quantum materials – itself disputed for reasons outlined below – quantum polymer research is the focus of pioneering scientists working in engineering, materials science and physics.
Quantum Materials
The term “quantum materials” has recently risen to prominence within the scientific community, thanks in large part to a 2016 article in Nature Physics, “The Rise of Quantum Materials”. The article outlines a history of condensed-matter physics, the area of physics that is concerned with matter’s physical properties at the macroscopic and microscopic levels and the physical laws that govern them (including electromagnetism, mechanical laws, and quantum mechanics). The article goes on to concede that “on a trivial level all materials exist thanks to the laws of quantum mechanics”, but still asserts “there are good reasons to embrace quantum materials”.
In other words, while the concept of quantum materials may be seen by some as too broad a topic – all materials have quantum mechanical behaviors – discussion and research in the rising field of quantum materials is still important, as it provides a “common thread linking disparate communities of researchers” (The rise of quantum materials, 2016). One of these disparate research communities linked by quantum materials is quantum polymer research, especially the recently discovered class of quantum tunneling composites.
Polymers
Polymers – from the Greek polus, which means “many” or “much”, and meros, meaning “part” – exist both synthetically and organically. The most well-known types of polymer are synthetic plastics such as polypropylene (used to make rope) and polystyrene (used for all kinds of packaging applications). Organic polymers include biopolymers like DNA and protein and natural polymeric materials like hemp, wool and amber.
Due to their large molecular mass and small molecule compounds, polymers are tough, both viscous and elastic, and take glass or semicrystalline forms rather than crystals. For these reasons, they have been used for centuries to create rope and textiles and make the perfect materials for long strands of molecules like those that exist in DNA and proteins.
Quantum Tunneling Composites
Quantum tunneling composites (QTCs) are materials that exploit the quantum mechanical effect known as quantum tunneling. Quantum tunneling is a phenomenon observed at the quantum scale where subatomic particles are can through a potential barrier, rather than requiring enough potential energy to break through the barrier as a larger particle governed by the laws of classical mechanics would need.
David Lussey, a technician, discovered QTCs in 1996 while he was researching electrically conductive adhesives. He found that combining a class of polymer composites known as elastomer – which have high viscoelasticity, weak intermolecular forces, low stiffness (Young’s modulus), and high failure strain – with particles of metal (nickel in this case) produced a new composite which could uniquely exploit the quantum tunneling phenomenon.
QTCs produce an electric current when pressure is applied to them. This comes from their surface which consists of silicon spikes. The spikes are not close enough to touch one another, but when pressure is applied they move closer together. This results in electrons flowing between the spikes – a quantum mechanical effect – and producing current. However, there is no chance of arcing (electrical sparks occurring), and no contamination or interference within the QTC is possible due to there being an airless gap inside.
QTCs reduce in electrical resistance as soon as pressure is applied, which allows electrical current to flow. The amount of pressure applied directly correlates with the amount of electrical resistance (and therefore current), meaning QTCs provide “a level of control, reliability, and range” that cannot be achieved with classical piezoelectric materials due to the linear electrical resistance that they exploit (Peratech, 2016).
Lussey has since founded Peratech, which holds the intellectual property on QTCs, in order to further exploit and market applications of these unique properties of quantum polymer-based materials.
Sources
- The rise of quantum materials. (2016). Nature Physics, 12(2), pp.105–105.
- Peratech (2016). Peratech - What is QTC? Peratech.com. [online] Available at: https://www.peratech.com/ [Accessed 14 Sep. 2019].
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