Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

done today.
    NANOCARS IN OUR BLOOD
    One step beyond the nanoparticle is the nanocar, a device that can actually be guided in its travels inside the body. While the nanoparticle is allowed to circulate freely in the bloodstream, these nanocars are like remote-controlled drones that can be steered and piloted.
    James Tour and his colleagues at Rice University have made such a nanocar. Instead of wheels, it has four buckyballs. One future goal of this research is to design a molecular car that can push a tiny robot around the bloodstream, zapping cancer cells along the way or delivering lifesaving drugs to precise locations in the body.
    But one problem with the molecular car is that it has no engine. Scientists have created more and more sophisticated molecular machines, but creating a molecular power source has been one of the main roadblocks. Mother Nature has solved this problem by using the molecule adenosine triphosphate (ATP) as her energy source. The energy of ATP makes lifepossible; it energizes every second of our muscles’ motions. This energy of ATP is stored within an atomic bond between its atoms. But creating a synthetic alternative has proven difficult.
    Thomas Mallouk and Ayusman Sen of Pennsylvania State University have found a potential solution to this problem. They have created a nanocar that can actually move tens of microns per second, which is the speed of most bacteria. (They first created a nanorod, made of gold and platinum, the size of a bacterium. The nanorod was placed into a mixture of water and hydrogen peroxide. This created a chemical reaction at either end of the nanorod that caused protons to move from one end of the rod to the other. Since the protons push against the electrical charges of the water molecule, this propels the nanorod forward. The rod continues to move forward as long as there is hydrogen peroxide in the water.)
    Steering these nanorods is also possible using magnetism. Scientists have embedded nickel disks inside these nanorods, so they act like compass needles. By moving an ordinary refrigerator magnet next to these nano-rods, you can steer them in any direction you want.
    Yet another way to steer a molecular machine is to use a flashlight. Light can break up the molecules into positive and negative ions. These two types of ions diffuse through the medium at different speeds, which sets up an electric field. The molecular machines are then attracted by these electric fields. So by pointing the flashlight one can steer the molecular machines in that direction.
    I had a demonstration of this when I visited the laboratory of Sylvain Martel of the Polytechnic Montréal in Canada. His idea was to use the tails of ordinary bacteria to propel a tiny chip forward in the bloodstream. So far, scientists have been unable to manufacture an atomic motor, like the one found in the tails of bacteria. Martel asked himself: If nanotechnology could not make these tiny tails, why not use the tails of living bacteria?
    He first created a computer chip smaller than the period at the end of this sentence. Then he grew a batch of bacteria. He was able to place about eighty of these bacteria behind the chip, so that they acted like a propeller that pushed the chip forward. Since these bacteria were slightly magnetic, Martel could use external magnets to steer them anywhere he wanted.
    I had a chance to steer these bacteria-driven chips myself. I looked in a microscope, and I could see a tiny computer chip that was being pushed byseveral bacteria. When I pressed a button, a magnet turned on, and the chip moved to the right. When I released the button, the chip stopped and then moved randomly. In this way, I could actually steer the chip. While doing this, I realized that one day, a doctor may be pushing a similar button, but this time directing a nanorobot in the veins of a patient.
    One can imagine a future where surgery is completely replaced by molecular machines moving through the bloodstream, guided by magnets, homing in on a diseased organ, and then releasing medicines or performing surgery. This could make cutting the skin totally obsolete. Or, magnetscould guide these nanomachines to the heart in order to remove a blockage of the arteries
    Molecular robots will be patrolling our bloodstreams, identifying and zapping cancer cells and pathogens. They could revolutionize medicine.
    DNA CHIPS
    As we mentioned in Chapter 3 , in the future we will have tiny sensors in our clothes, body,