Chiral (pronounced chiral after the Greek letter chi) is not a word that director Hideo Kojima made up during the development of Death Stranding. Sam Bridges' "Chiral Network" is obviously nonsense, but chirality is a general property that exists naturally in molecules and even light, and with a little help from us, is helping to create the electronics of the future.

Consider the mantis, a predatory crustacean. There are two types of this predatory crustacean: the crusher with a pair of legs adapted as a club, and the spearman whose appendage tips have evolved into barbed wire. The common denominator of both is the extraordinary eye. They have up to 16 types of photoreceptor cells (humans have only three), some of which can detect circularly polarized light. This circular polarization means that the light wave continues to move linearly, but the electromagnetic field rotates perpendicular (at right angles) to its direction. Photographers know that by screwing a circularly polarized filter into the lens of their camera, they can increase the saturation and contrast of a scene and slightly reduce its brightness

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Thus, chirality can be thought of as the direction of the hand, or helix. It can twist to the left or to the right. Think of your own hand. If you put the palms of your hands together, the shapes are congruent, but if you put one on top of the other, they are obviously different. Chiral structures are everywhere: the shell of a snail, the shape of a pasta dish, the screws that hold a desk in place. In the molecular world, chirality is important. A cluster of twisted atoms on one side may relieve a stuffy nose, but a spiral on the other side is a stimulant. Please don't write that crystal meth also relieves nasal congestion. [Dr. Jessica Wade, who studies circular polarization in the Department of Chemistry at Imperial College London, says. 'We use chiral materials in LED displays, computers, and cell phone screens. Currently, there is an anti-glare filter in front of the OLED pixels, which is essentially made of a circular polarization filter. However, if a pixel emits light that is not polarized 50% leftward and 50% rightward, half of the light will be lost in that filter. In other words, a huge battery is consumed to pass as many photons as possible through this filter. If we could make the light essentially circularly polarized, we could increase the efficiency of the screen, which would greatly improve battery life."

Power efficiency is a major issue in computing, especially as power-hungry 5G connections continue to roll out across the country. Screens consume a lot of energy when they are on, while cell phones spend much of their time with the lights off. However, with a laptop PC, the screen is likely to be on all the time it is in use, significantly reducing battery life. The human eye cannot distinguish between left- or right-handed rotation (with all due respect to the shako-shrimp here). Says Wade, "If you want to encode something and you make its light sequence chiral, you can only really detect it if you know it's what you're looking for." [Almost everything in the human body is chiral. Sugar is chiral, DNA is chiral, amino acids are chiral. Sugar is chiral, DNA is chiral, amino acids are chiral." How cool would it be if we could use chiral structures to generate circularly polarized light or manipulate the quantum properties of electrons?

We are far beyond high school physics classes here. Electrons exist as pairs and the different quantum states are called "spins". It has been shown that as electrons move through chiral matter, they can be filtered by their spin depending on how much matter they have. [There is a branch of electronics called spintronics that affects something we are all familiar with: hard disk drives. The first storage device to use "spin valves," which alter the magnetic state of materials at the molecular level with data storage in mind, was the massive 16.8 GB IBM Deskstar Titan, introduced in 1997. These days, all rotating hard disk drives use this technology to some degree, greatly reducing the number of magnetic impulses that can be detected as the read head moves across the surface and increasing the data density available for writing.

"Chiral materials have all these attractive properties at room temperature," says Wade.

"To achieve spintronics, we would have had to make something like liquid helium at very low temperatures, but with chiral materials, we can achieve spintronics on a small scale without having to make expensive inorganic materials." Because Wade is a chemist, she uses "inorganic" to mean non-carbon-based materials. She is working with graphene-based carbon, but graphene itself is flat and cannot be made chiral.

I have often talked in this column about using new materials to enhance familiar processes, and I have reached there again. Kojima may have come up with a novel idea with Death Stranding, but the science behind it is sound and will likely affect all of our lives in the future, even if it doesn't lead to an Internet connection running at the speed of light.

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