Wonders of nanotechnology and material science

Aoife describes the origins of nanotechnology and material science and discusses their potential applications in medicine and agriculture

SCITECH

“As soon as I mention this, people tell me about miniaturization, and how far it has progressed today. They tell me about electric motors that are the size of the nail on your small finger. And there is a device on the market, they tell me, by which you can write the Lord’s Prayer on the head of a pin. But that’s nothing; that’s the most primitive, halting step in the direction I intend to discuss. It is a staggeringly small world that is below. In the year 2000, when they look back at this age, they will wonder why it was not until the year 1960 that anybody began seriously to move in this direction.” Richard Feynman, “There’s plenty of room at the bottom”-1959

In 1959, Professor Richard Feynman delivered a lecture to the annual meeting of the American Physical Society at the California Institute of Technology (Caltech) where he described the possibilities of nanotechnology, a term that would not appear in scientific literature for another 15 years.

The birth of nanotechnology

‘In 1974, Professor Norio Taniguchi of Tokyo Science University first coined the term nanotechnology describing the “precision machining of materials to within atomic scale dimensional tolerances”’

Remarkably, nanotechnology was not a twenty-first century discovery and surprisingly dates back much further than Feynman’s famous 1959 lecture.

Strong evidence of nanostructured materials by skilled craftsmen who understood the effect of heat on certain materials dates as early as the fourth century. About 1,600 years ago, the Lycurgus Cup was probably believed to possess magical properties. In the presence of an external light source, the Roman chalice appears opaque green, but changes dramatically to translucent red when the light shines from within. This is not due to the casting of a Colovaria charm or any other Harry Potter magic but rather is a perfect example of the technical skills possessed by early Roman artisans who engineered dichroic material by mixing glass with 50nm (a nanometer is 1 millionth of a millimeter!) colloidal gold and silver nanoparticles.

In 1974, Professor Norio Taniguchi of Tokyo Science University first coined the term nanotechnology describing the “precision machining of materials to within atomic scale dimensional tolerances.” Nanotechnology and material sciences were then officially born. Over the last 50 years this field has advanced rapidly to what seems like nearly science fictional heights. From nanoparticle-eating worms to robotic skin capable of sensing the world around us, here’s a look at what this flourishing field of science fact has in store for us.

Nanotechnology in Medicine and Agriculture

“In this BioX seed grant study, however, the worms spend their day munching on nanoparticles encapsulating their favourite bacterial snack”

Nanoparticles have made headlines in recent years as tiny, but crucial, players in modern medicine — proving my mum was right when she told me the best things come in small packages — and boy do they pack a punch! Clinical applications using nanoparticles range from vaccines and drug carriers to gene delivery vehicles. Even contrast agents used for radiology imaging are comprised of nanoparticles.

However, two research labs in Stanford University have taken Nanomedicine to a whole new level of weird and wonderful. The groups, lead by Professors Jennifer Dionne & Miriam Goodman, research tiny worms which though small  in size have the very long Latin name Caenorhabditis elegans or C.elegans for short. This transparent nematode is approximately 1mm in length and normally lives in temperate soil environments. In this BioX seed grant study, however, the worms spend their day munching on nanoparticles encapsulating their favourite bacterial snack.  When excited by a near-infrared laser, the inorganic nanoparticles emit light of different colours depending on the environmental pressures surrounding them. This allows the particles to release real-time data relevant to the particular forces they are undergoing while inside the worms. This research is particularly useful for understanding the role of tissue force generation. According to Professor Dionne, “altered cellular-level forces underlie many disorders including heart disease and cancer.” By accurately detecting cellular forces within our own bodies at an early stage we could treat and potentially prevent certain diseases thanks to the pioneering research carried out in these tiny worms.

Speaking of nematodes, a research team in The University of Queensland has recently discovered an environmentally sustainable pesticide to protect plants from pathogenic viruses that could prove to be an invaluable addition to current crop protection measures. BioClay, is a sophisticated nanomaterial produced by loading double-stranded RNA which induces virus resistance in plants onto layered double hydroxide (LDH) clay nanosheets. The dsRNA loaded onto this clay “face mask” for plants tricks it into thinking it is under attack and prompts a protective response against future infections. LDH is non-toxic, degradable, and can be sprayed directly onto plant leaves and is detected up to 20 days after a single spray!

The majority of breakthroughs in nanotechnology and material science occur in healthcare and agriculture which, let’s be fair, are pretty important sectors of society to apply our expanding knowledge of this field. But, if you’ve recently watched Westworld, HBO’s new series set in a wild west theme park inhabited by disturbingly life-like robots, you’ve probably wondered how close we actually are to creating such realistic automatons. The scary or perhaps exciting answer, depending on your point of view, is pretty close.

Nanotechnology and “smart skin”

“Synthetic, self-powered skin that has the potential to enable robots to physically sense the world around them”

Last year Professor Haixia Zhang and her research group from Peking University in Beijing published a paper in ACS Nano on “smart skin technology”. This is a synthetic, self-powered skin that has the potential to enable robots to physically sense the world around them. This transparent skin detects contact location and velocity of the object it is sensing resolves many of the previous problems associated with other prototypes that required many power-supplying electrodes to boost sensitivity and precision.

This superior smart skin requires just four electrodes (others require up to 36) comprised of silver nanowires and, amazingly, can also harvest mechanical energy and convert it to an electrical current. Microstructured poly films allow this technology to be merged onto human skin for use in prosthetics. When tested in the lab, the smart skin was capable of sensing a honey bee flying towards it! These advances have the potential to incorporate a high level of flexibility and sensitivity into prosthetics, but also may give a new “life” to a generation of androids that are capable of sensing the environment around them.

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From dichroic chalices developed centuries ago to robotic smart skin that can “feel” the world around it, nanotechnology has come a long way. Richard Feynman predicted the future of an unnamed field of science during his 1959 lecture in which he imagined a nanoworld filled with endless possibilities.