It is said the all things begin small. Nanotechnology is not an exception, beginning with a lecture at Caltech by the famous physicist Richard Feynman. In the December 1959 meeting, he proposed the possibility of a new synthetic chemistry by the direct manipulation of atoms. Feynman also proposed that it might be possible to build nanoscale machines that can synthesize chemicals and even heal you from the inside. In the 58 years since the famous speech, many of Richard’s predictions have been realized in the laboratory. Outside of scientific research, it has been a long road to the commercial adoption of the technology. Part of this is the challenge of manipulating atoms on the nanoscale, which translates to one billionth of a meter. All nanotechnology development is interested in building structures that measure between one and one hundred nanometers. The other challenge is the unresolved toxicity and pollution of the new technology. Notwithstanding the problems, three companies have succeeded in the challenge of bringing it to the market.
Carbon nanotubes have been one bright side of the research. Like diamonds, carbon nanotubes are a specific molecule of carbon atoms arranged in tubular structures. They are awesome on account of their extraordinary tensile and electrical properties. They are also supremely difficult to produce and have only been used as an ingredient in bulk materials.
Twelve years ago, the Finnish company successfully developed the Hybtonite epoxy by accident. Giant carbon nanotube molecules made by Bayer are the primary ingredient but have long been difficult to use because they don’t typically bond with the chemical base. Poor bonding results in inferior strength in composites, which is unacceptable. The company partnered with researchers at Nanolabs Systems Oy, located in Jyväskyla Finland. Quite by accident, the scientists discovered that ultrasonic vibration could force the carbon molecules to chemically react with an amine resin to form a very resilient resin.
The resin is then chemically activated to form a very useful epoxy. The resulting epoxy has proven very effective in the manufacture of composite materials used in everything from wind turbines, marine paints, skis, ice hockey sticks, hunting arrows, and even surfboards.
The Boeing Company is partnering with PPG Aerospace and Gentex Corporation to feature smart windows on all its Dreamliner aircraft. Replacing the usual sliding shade, the darkness of the windows can be adjusted with a dial. The windows are also known as Electrochromic devices. The magic all begins with nanotubes mixed with a liquid electrolyte sandwiched between two electrodes. The electrodes are further embedded between the two panes of glass.
The darkness of a smart window is adjustable by changing the voltage between the electrodes. Amazingly, the window is only clear when a voltage is applied. The applied voltage forces the nanotubes to line up in neat rows, producing a lovely clear view of the clouds below. Remove the voltage, and the nanotubes clump up dimming the window.
In real life, it is more complicated. The windows have about a five-minute response time to the application of the voltage, and passengers have complained that the window never gets completely black. Annoyingly, travelers can still see the outline of land when the window is completely dimmed. Commuters have also complained that the windows develop a purplish hue. Notwithstanding the bugs, it is still a significant development towards the commercial production of nanotechnology.
Founded in 2008 at the Massachusetts Institute of Technology, the company has developed a new form of capacitor. At their core, capacitors are very simplistic electronic devices. Two plates separate a dielectric, and when a voltage is applied, an electric field forms across the insulating dielectric. Since the dielectric is an insulator, the positive and negative charges accumulate on the plates forming capacitance. The available plate area and the performance of the dielectric limit the capacitance of the devices.
FastCAP has dramatically raised the surface area by applying carbon nanotubes to the plates. Specifically, they discovered that by tightly packing the carbon nanotubes in vertical arrays aligned with the plates, the company could radically raise the surface area. By 2012, the company had a functional ultracapacitor that could tolerate high temperatures and would not explode if damaged. In the five years since the rollout, the company has built communications equipment powered by the ultracapacitors for use in oil drilling.
Further developments in capacitor technology have resulted in devices that can withstand very low and very high temperatures, making them suitable for space applications. NASA is interested in replacing batteries on small satellites that are also known as CubeSats. The capacitors could also be productive in powering actuators that separate rockets during staging. The company is also investigating methods for enhancing hybrid automobiles. The capacitors could be useful storage devices for capturing energy from braking, or as a substitute for conventional batteries when starting the engine. Another possibility is that the capacitors could capture the energy from fuel cells in an automobile.
For all the capabilities of ultracapacitors, they are not without their limits. On average, conventional lithium-ion batteries can store twenty times more energy than a capacitor. Technology maturity has also made batteries about twenty times cheaper than a comparable capacitor. Batteries can also tolerate higher voltages than capacitors, but can’t tolerate extreme temperatures. Batteries also have the benefit of providing a constant discharge voltage, which is difficult to achieve with capacitors.
The advantages of capacitors are that they are generally insensitive, and don’t readily explode when tampered with. Just don’t charge them at the wrong polarity. Capacitors can also be charged and discharged very quickly and can be cycled thousands of times more than a battery with no loss of capacity. With no chemical elements: capacitors are generally not susceptible to the degradation of batteries, but there are exceptions. Capacitors also have the advantage that they can be cycled in seconds instead of minutes, and they are much more tolerant of extreme temperatures.
Even with all the limitations, it is still a striking advancement in nanotechnology.