Google the word “machines” and click on images search results. The webpage will present you thousands of huge and multifaceted designs. These equipment usually have elaborate configuration of gears, dynamo, flywheel, gaskets, spindle, valves and shafts. Typically, these machines are used in manufacturing, transportation and in construction industry. Now, ask a kid or even a grown-up to give examples of machines. Automated robots or even the transforming ones will certainly top the list. Gone are the days when people only used classical tools like lever, wheel and axle, pulley, inclined plane wedge and screw. Our modern society are now gearing up in inventing automated machines like the world’s strongest robots, Fanuc M-2000iA/1700L (2015) and Kuka Titan (2007). Having a payload capacity of 1700 kg and 1000 kg, respectively, these machines can lift an entire car and defy gravity. In contrast, to craft large machines was not the focus of the recently Nobel Prize awardees in Chemistry. Three scientists, Frenchman Jean-Pierre Sauvage, British-born Fraser Stoddart and Dutch scientist Bernard Feringa created the world’s tiniest machines not even in a micrometer scale but of the nanometer scale. This is one thousand times smaller than the width of a hair, or a billionth of a meter. This breakthrough would make us want to refresh what is really a machine and would likewise make us wonder what applications a molecular machine can cater.
Machine is described as tool comprising one or more components that uses energy such as chemical, thermal, or electrical means to execute a projected task. These are devices that transmits or modifies force or motion. . The Nobel Prize awardees concentrated on the use of molecules which utilize chemical attractions and cohesions to construct molecular chains, cars, axles, elevator, muscles, and even computer chips. First on the discovery was on 1983 when Jean-Pierre Sauvage created catenanes. These are molecular interlocking chains and rings used on connecting parts needed for molecular motors. Together with his group, Sauvage effectively devised a new method to bind molecules together by using a mechanical bond instead of a chemical one. He placed a molecular ring around a copper ion and then looped a C-shaped molecule through the ring. The ion finely held both molecules in place until the scientists could connect a second C-shaped molecule to the first one, effectively closing the hoop. The ion could be removed creating a two-link chain. Sauvage’s team succeeded to make one ring rotate around another by adding energy. It is analogous to a fan which can rotate when plugged into an electrical outlet.
In 1991, rotaxane was successfully created by Fraser Stoddart. It is a ring-shaped molecule threaded on an axle like a dumbbell shaped molecule. The axle’s both ends has stoppers so when the ring shunt back and forth, it is easily controlled. Stoddart and his team regulate that process by using variations in acidity, light or temperature. Rotaxane became the first molecular shuttle. Eventually, Stoddart managed to construct a minuscule elevator, which can raise itself about 0.7 of a nanometer; design an artificial muscle by threading two loops of molecules together which rotaxanes bend a thin sheet; and even build a tiny computer chip with 20 kilobytes of memory. Millions of rotaxanes were used to create high-density memory device. Such device can stores the zeroes and ones of binary information in the switchable states of organic molecules. It contains 160,000 memory elements, each with an area of just 30 nanometres square — approximately 40 times smaller than today’s existing devices
Lastly, Bernard Feringa’s work in 1999 paved on building the world’s first synthetic molecular motor. It is a tiny spinning blade connected by carbon–carbon double bond that rotates continually on an axis until the bond was broken with light. In 2014, it rotated at a speed of 12 million revolutions per second. His team also created a four-wheel drive nanocar in 2011. In addition, he also used molecular motors to spin a glass cylinder that was 10,000 times bigger than the motors themselves.
Their remarkable discoveries are unimaginable and could impact almost all sectors of our society like health care and electronic industry. “In terms of development, the molecular motor is at about the same stage as the electric motor was in the 1830s, when researchers proudly displayed various spinning cranks and wheels in their laboratories without having any idea that they would lead to electric trains, washing machines, fans and food processors,” said the Nobel committee. For now, it’s uncertain what the next big development will be, scientists said. “If I could tell you that, I would be running along to my lab and doing it now,” Stoddart said in an interview. “But in terms of generalities, I will say that it will be mind-blowing, what can be done even in 10 years’ time, let alone 50.” On the other hand, Feringa had a more particular list in mind. “Think about tiny robots that the doctor in the future will inject in your blood veins and that go to search for a cancer cell, or go in to deliver drugs,” he said during a conference in Stockholm. “There are also smart materials, for instance: materials that can adapt, change, depending on an external signal — just like our body functions.”
These discoveries when combined and studied further could someday lead to awesome sensors, batteries, molecular computers and storage, targeted medical therapies and energy-storage systems. “Chemistry has thus taken the first steps into a new world,” the Nobel Prize committee said in a statement. “Time has clearly shown the revolutionary effect of miniaturizing computer technology, whereas we have only seen the initial stages of what could result from the miniaturization of machines.”
By: Sarah May G. Cruz
