Graphene World's Smallest Car Force Testers Composite Cans
Today on "how it's made"... In 2004, british scientists extracted a substance called graphene from graphite, which is the material used to make pencils. They won the nobel prize for this discovery and left their mark on physics history. Scientists continue to explore graphene's extraordinary potential. These silicon chips are dyed with thin flecks of carbon, known as graphene. Just one atom thick and transparent, graphene can sniff out chemicals in the air and disease enzymes in blood. This lab manufactures graphene using a process known as chemical vapor deposition. A technician loads a capsule containing a copper foil sheet into a furnace. He screws a cap on the end of the capsule and shuts the furnace. He activates a system that uses argon gas to drive out oxygen. When the furnace reaches about 1,800 degrees fahrenheit, methane gas and hydrogen are added. A reaction occurs that deposits graphene onto the foil. Graphene can't be seen with the naked eye. A technician applies tiny gold contacts to a silicon wafer and then submerges it in solvent to rinse off the excess gold. The remaining gold bits serve as electrical contacts. A dip in acetone cleans off more of the loose flakes, and a final rinse in alcohol removes the rest. Using a diamond-tip scribe, he scores the silicon wafer and breaks it along the score lines, creating rectangular chips. Another technician deposits liquid plastic onto the transparent graphene on the copper foil. He locks the foil in a machine called a spin coater. It spins at 3,000 r.p.m. this spreads the plastic evenly across the graphene film on the foil. It also accelerates the plastic's curing process. He then separates the plastic-coated graphene from the copper foil. To do this, he clips a wire to set of tweezers. Using the tweezers, he picks up a small piece of the plastic, graphene, and copper sandwich and plunges it in the water. The tweezers apply an electrical charge through the copper, causing bubbles to form in the water. These bubbles lift the graphene and plastic film away from the copper. The graphene now clings only to the plastic backing. He scoops the plastic-backed graphene square out of the water using a large piece of plastic. To remove contaminants, he immerses the square in a series of solutions. In the last solution, he slides the square off the carrier. And the square floats freely. He picks up the silicon chip with tweezers and uses it to retrieve the floating graphene and plastic square. It now sits on the silicon chip. After taping metal stencils over three of the graphene-covered chips, he suspends them above gold pellets in a machine known as the evaporator. He closes the evaporator, then turns up the heat. A vacuum pulls the gold toward the stencils as it evaporates. The gold and exposed graphene adhere to one another as they cool and solidify. The technician removes the stencils from the chips, revealing gold horizontal runners between the gold contacts. He transfers the chip to a plasma etcher. He activates the chip, and plasma gas floods the chamber. The gas strips off any graphene that's not protected by gold. Only the gold contacts and gold-covered graphene runners remain on the chip. Solvent dissolves the plastic backing on the graphene runners, taking the protective gold with it, leaving only graphene. The technician now has a graphene sensor chip. It's time to test its sensory powers using antibodies for a certain disease protein. The antibodies attach to the surface of the graphene. She tests the signal from the chip to confirm that it reads the protein correctly. This graphene chip is ready to act as a high-tech sixth sense. The world's smallest car has held the guinness book of world records title for more than 50 years. Designed and manufactured in the u.k., it's about 6 feet long and 3 feet wide. It fits one driver but no passengers. Intended as a commuter vehicle, the world's smallest car travels up to 40 miles per hour. Technicians craft the body in molds section by section. First, they spread an epoxy resin in the customer's color choice. Once the resin cures, they lay a sheet of fiberglass matting and impregnate it with resin. This bonds the matting to the gelcoat layer. Narrower strips of matting are applied around the perimeter. Certain areas are reinforced with a more porous fiberglass matting to absorb more resin. Finally, a second layer of fiberglass matting and resin is set over the entire mold. The molds cure for a day. When they're ready, the body sections are extracted from their molds. This is the main section. The gelcoat forms a smooth and shiny finish on the sturdy fiberglass underneath. Using a saw equipped with a small blade, technicians smooth the edges of the fiberglass. Elsewhere in the factory, technicians weld together the car's lightweight aluminum gas tank. It holds 1 gallon of gas. They drill a hole through it... Then weld on the filler tube and screw on the cap. The car runs on three wheels-- two at the front and one driven by the engine at the back. Technicians assemble the wheel hubs, then mount them onto the triangular suspension of the axle. They flip over the steel chassis and install the disc brakes on each wheel. On the rear wheel, they mount a sprocket, which allows the engine to drive a chain that rotates the wheel. They connect the shock absorber on the rear wheel to a mount underneath the body and install hydraulic brake lines and brake calipers on all three wheels. They bolt the wheels and tires onto the wheel hubs. Each tire is about 6 inches in diameter. After installing the one-cylinder engine in the middle of the body, technicians bolt on the chassis. They connect the shock absorber on the rear wheel to a mount underneath the body. They install all the electrical components, such as the headlight, the brake lights, the turn signals and the wiper. The car can be ordered with an electric engine, in which case they install four 12-volt rechargeable batteries. The car has a rack-and-pinion steering system. The steering column is attached to a circular gear, called a pinion. When the driver turns the steering wheel in one direction, the pinion moves in that direction along the rack. The rack is a track with teeth, connected by rods to the front wheels. It moves and turns the wheels, steering the car. The vehicle is mechanically complete. Now, they install the windshield and windows, sealing the aluminum frames with silicone. Inside, they mount the steering wheel and the dashboard, which houses the speedometer, turn signal light, and high beams. They hang the door, which has been fitted with chromed hinges and a handle. The style is consistent with the 1960s design of the car. They finish the job with the installation of a vinyl driver seat, gas tank, and windshield washer fluid reservoir. The world's smallest car is ready to hit the road and make a big impression. Force testers pull and compress products to their breaking point. They're used in labs and factories to evaluate a product's quality. A force tester verifies that an object meets the manufacturer's required specifications. Force testers are built to pull and compress. Here, a tester arm bears down on a pencil. It determines how much force can be applied before the pencil bends or breaks. Measurements are displayed on a screen. In the 1930s, basic force gauges were attached to cranes to measure a product's strength. Today's force testers are high-tech. They have digital displays and computerized controls. An assembler starts by screwing brackets into a steel base for the main computer board. The computer board comes next. He uses nuts, called standoffs, to raise it above the steel plate. This creates an air space between the two, preventing electrical shorting. Throughout the assembly, the technician wears an electrostatic discharge band on his wrist. This arrests static electricity to prevent damage to the parts. He screws the motor drive board to the force tester base and moves on to the next batch of parts. They include the power supply board, a mechanism to turn the unit on, and an emergency stop assembly. He routes the wires for the power switches and installs the push buttons. He connects a ribbon cable to the main circuit board. Then, he attaches the other end of the cable to the motor drive board. This allows them to communicate. Finally, he completes the power supply connections. Another member of the team assembles a vertical support rail to an aluminum base. This rail is the backbone of the tester. It supports the force arm and the track it moves on. He attaches the track to the support rail. Using an alignment tool, he slides the shuttle into the grooves of the track, then confirms it moves freely. He's ready to mount the force arm to the shuttle. A long, threaded rod, known as a lead screw, is fastened to the force arm. The lead screw rotates, allowing the force arm to move up and down. He lowers an aluminum cover over the force arm assembly and secures it to the base. One side of the casing is open. He'll install an accordion-style rubber curtain to it later. Next, he threads a rubber belt around a pulley, which is attached to the end of the lead screw. He installs the motor and wraps the other end of the rubber belt around the motor pulley. The motor drive assembly turns the lead screw to move the force arm. The base is now mounted with the electronics to the force tester frame. After connecting switches that limit the force arm's range of movement, he installs an encoder on the motor to provide feedback on speed and power. The electronics are covered with a tough plastic casing. Next up is a slotted table. He clips a computer tablet to the tester. An adjustable bracket is attached, which is used for changing the screen's position as desired. A force tester doesn't just bear down on things. It also pulls things apart. A technician conducts a pull test on a piece of nylon cord. He activates the force arm. The force arm pulls the cord as it grips the base. The tester measures the peak force required to pull the cord apart. The results are displayed instantly on the control screen. There are different force testers for different applications. But the purpose is always the same-- pull and compress objects in order to test their limits. One of the ways a manufacturer can package a product is in a composite can. It's a cylindrical container made of cardboard with a moisture barrier lining. Composite cans are less expensive to produce than glass or metal containers. And they're recyclable. Many products are packaged in composite cans, everything from automotive grease to parmesan cheese. The cans are cardboard with an interior lining that prevents it from absorbing moisture. The top can be a sifter, a pull-tab cap, a ring and plug, or peel-off foil. To make composite cans, they begin winding a strip of thin paper over a long steel rod, called a mandrel. The machine applies glue to the top of the strip. Simultaneously, two strips of cardboard wind off rolls and pass over a glue applicator, which coats their underside with adhesive. Then these overlapping twin strips wind around the coated paper-wrapped mandrel. The adhesive binds the layers, producing a two-ply cardboard tube with an interior moistureproof lining. The machine pushes the tube off the mandrel to an automated circular saw. The saw cuts the tube into shorter pieces. They fall into a bin, which feeds the labeling machine. Suction cups pick up the sheet of labels and run it over a glue roller. It applies adhesive to the back side. A vacuum carpet carries the label onto another set of mandrels. The machine slips the tube onto the mandrel, then wraps the label around the tube. Next, knives cut the spinning tube into seven cans. The can-making line has been slowed by our camera. At the regular output speed of 250 cans per minute, all you'd see is a blur. A pusher moves the cans toward a device called an upender, which stands each can upright. The cans then spin through a gluer, which applies a bead of adhesive along the top rim. Meanwhile, another station lines up the closures in single file. These cans are for parmesan cheese, so the tops are plastic sifters. They go one by one onto a carousel. The tops align with cans on another carousel with perfect timing. A plunger pushes the top about a 1/2 inch into the glued rim of the can. As the cans exit the machine, a conveyer turns them upside down. The cans reach the end of the line, where workers stack them on shipping pallets. The parmesan cheese producer will receive them like this-- open end up, ready for filling. To make the metal bottom for the can, a punch press stamps circles out of a strip of tin that's been coated with a food-safe lacquer. The gold-colored coating prevents the tin from rusting when it comes into contact with the moisture in the cheese. The next machine uses forming rollers to shape the rim that will grip the can. This production line is making composite cans for grease cartridges. Mechanics use them in a device similar to a caulking gun. For this product, the cardboard tube has a plastic-coated liner. The liner is heat-sealed to the cardboard to prevent grease from leaking out. The closure is a rigid aluminum top that you remove with a pull tab. This machine, called a seamer, crimps the metal edge tightly around the can's rim. As the cans exit the machine, a computer takes measurements of each top. If it doesn't meet specifications, the machine ejects the can from the line. The cans that pass inspection continue on to the packaging area, where an employee does one last visual inspection before shipping to the grease manufacturer. Once a composite can is empty, the cardboard can be separated from the metal and tossed into a recycling bin.