The widespread use of computers in the lastcentury has radically changed the economy,society and even our personal lives! And, like any useful machine, engineers arealways looking for new ways to build and improve them. If you need evidence of how good a job engineershave done at making computers smaller, faster & moreefficient, try using an old cell phone from the 90s. But the relationship goes both ways. While engineers are making more effectivecomputers, computers are making more effectiveengineers. Computers are a little tricky to define, butgenerally, you know one when you see one. Technically, they’re machines that perform, or‘compute,’ a series of mathematical calculations, likeaddition or subtraction, usually with electronic circuitry. The exact nature of those calculations dependson the electrical inputs to the computer, and theyhappen much faster than humans are capable of. Computers also have machinery that storesthe states associated with its electrical inputsand outputs, called memory. But they’re so much more than glorifiedcalculators! Because computers can execute different kindsof computer programs using the same physicalhardware, they’re incredibly versatile tools. But to be useful, computers need computerengineers. Like in other fields of engineering, computer engineersare concerned with improving the various parts of acomputer and developing new ways to use them. Usually, that involves dealing with two maincategories: hardware and software. Hardware consists of the physical parts ofa computer. The exact components can be differentdepending on what the computer is for, but virtuallyall computers have two core parts: memory, and a central processing unit, orCPU, which executes computer programs. The CPU contains the electronic circuitrythat actually performs calculations. It can also coordinate the different processeshappening in a computer simultaneously, and allocatescomputing resources to different tasks. Memory, meanwhile, can serve a few differentpurposes. 

Computer memory provides the physical spacewhere computer outputs can be permanently stored, like that picture you took of yourcat trying to fit into a tiny box. It also provides a temporary working spacefor a CPU to store relevant bits of informationwhile it carries out a task. The signals carrying that information, evenif they were originally recorded as analogue,are passed between computers in digital form. With digital signals, the voltages in thecircuits occupy binary states – some form of‘on’ or ‘off’ – that represent 1s and 0s. Binary is the underlying representation thatcomputers use to operate. As a human, though, you’re not going to sit there andmanually send an enormous string of voltage signals toa CPU yourself, unless you have a lot of time to spare. That’s why computers tend to have whatare called peripherals – things that make iteasier for people to actually use them. That might include a set up like a keyboardand mouse for sending signals to a computer. To see what your computer outputs, likethis video, you’ll probably have a screen anda speaker somewhere on the device. In some cases, like on a touch screen, theinput and output peripherals can even be thesame thing. Peripherals take human-style outputs, like keystrokeson a keyboard, and convert them into the appropriatebinary signal for computers to interpret and vice versa. Other hardware associated with computers includesthings like printers, sensors, and network cables. These are the sorts of things a computer engineermight bring their electrical engineering expertiseto design and improve. The other side of computer engineering involvessoftware. Unlike the hardware of your computer, which you need tophysically replace to change a computer’s capabilities, software can be added to or changed to producedifferent results with the same hardware. So it’s essentially the programs your computerruns. For example, you can write a piece of software to store the phone numbers and opening times of every pizza place in the area to your computer’s memory and retrieve it as needed. If you have a camera connected to a computer, you could even program the software to recognize when the pizza delivery person comes to your door and turn down your music so you can hear the doorbell. In short, software is how you tell a computerwhat task to perform. Writing software to accomplish a task on thehardware you have is what’s broadly knownas computer programming. Those are the two main elements of what computerengineers work with. On the hardware front, they find ways to physicallyimprove the capacity of the machinery that carries out computations, exchanges signals,stores them to memory, and connects everythingtogether. On the software front, computer engineeringhas a lot in common with programming. But in addition to programming specific tasks,computer engineers might, say, find the best way tocarry out a task on a given piece of hardware. Or they could find more efficient forms ofsoftware that make computer programs run faster. Besides for improving the general designsof computers, computer engineers can also apply those skills todeveloping specific devices for aerospace, transport, municipal engineering, medicine, andtelecommunications. So there are a lot of options! But you can get a sense of the sorts of thingscomputer engineers work on by looking at someof the challenges facing the field today. For example, you might have noticed that whenit comes to size, most commercial computershave been getting smaller over the years. Things like laptops, smartphones, and gamingconsoles are able to fit much more computingpower into smaller hardware. The reason that’s happened is because more andmore computer circuit components, like transistors,were developed to fit into less and less physical space. In fact, since the 1970s, the number oftransistors able to fit on a computer chip hasdoubled roughly every two years! That’s what’s known as Moore’s law,named after American engineer Gordon Moore. Moore’s law describes how engineers havemanaged to create more sophisticated computersin smaller physical spaces. But the law may not last much longer, becausewe’re approaching the limit of what we cando with electrons. Some think Moore’s law has already ended. Electrical components are meant to directthe flow of current in a particular way. For example, transistors use a smaller currentto stop and start the flow of a larger current. But that job gets tricky as you shrink thecomponents down.

A thin channel can often be hard for the electronsin the current to pass through. And if you’re packing all that circuitry right nextto each other, you also have to keep the currentfrom hopping from one circuit to another. Not to mention, you have to be able to makeyour transistors out of something. To keep shrinking them down to fit more ofthem onto a computer chip, you need to use lessand less material for a single transistor. Eventually, you’ll have to build your transistorfrom just a few individual molecules, or maybeeven just a few atoms. But you can’t really build with anythingsmaller than that! To reach the limit of tiny electrical components, engineers are looking into alternatives tothe standard way we’ve been constructingtransistors, like by using nanotechnology. Some nanoengineering designs aim to createtransistors that operate on a current of justa single electron. There are already chip manufacturers on theirway to developing transistors just five nanometerslong – so a few dozen atoms wide. But having a large number of transistors,while generally great for computing purposes,creates other issues. One major consideration is the energy computersneed. Like most sophisticated electrical devices,the internal circuitry consumes a lot of power. Providing all that power is becoming moreof an issue. Computers are being designed with greater processingpower in their CPUs and bigger amounts of memorystorage, which all generates more energy demand. Right now, about 3% of the energy producedon Earth is used for computing. So making computers more energy efficientwould not only reduce the amount of carbondioxide released from burning fossil fuels, but it could save large companies billionsof dollars. Engineers have a few tricks up their sleevesto try and tackle this. A lot of the actual energy consumption comes fromproducing the binary signals computers use, the 1s andthe 0s represented by voltages being turned on and off. In the memory, the smallest unit of that signal,called a bit, is stored by changing the state ofan electrical component, such as turning a transistor on or off, or bycharging up a capacitor. Switching a bit from a 0 to a 1 or vice versatakes some amount of energy. So engineers are looking into methods of computingthat can somehow keep the “1” bits intact as they’repassed through the circuit, so they don’t have to be rewritten duringprocessing, saving energy. On the software side, computer engineers are alsodeveloping algorithms, special sets of rules used incomputer programs, that work more efficiently. For example, they’ve developed ways of sorting and searching for information that require fewer calculations to be performed by the computer, which can also save lots of energy. Even better, using less electrical energymeans less heat building up within the computer, which in turn could allow computers to operatefaster. So that’s what engineers are doing for computers. But computers are also doing a lot for engineers. For example, computers are essential for thecontrol systems we’ve talked about, automating the measurement and adjustmentof industrial devices like heat exchangers to makesure everything operates smoothly. But computers can also help engineers designand create components for use in other fieldsof engineering. That’s accomplished by Computer Aided Designand Computer Aided Manufacturing, or as they’remore commonly called, CAD and CAM. 

CAD is the process of using special softwareto design two or three dimensional objectson a computer. With CAM, you take those CAD designs and manufacturethem. Both CAD and CAM allow for well designed,precise, and replicable components. For example, printed circuit boards, or PCBs,are found in lots of common household electronics,like remote controls. Designing them can be tricky, and you don’t want to haveto print several prototypes using an expensive materiallike copper to test each one as you improve the design. CAD software provides tools to model your designon a computer before physically manufacturing it. You can then check various design elementsin the model and simulate what might happenin your circuit before it even exists. That saves the material, energy, and timeneeded for testing physical components. In the same way, it’s easier to see if acomplicated system of gears and pulleys isgoing to work as intended on a computer, rather than having to assemble them every time. Plus, CAD designs are useful for detailing theexact specifications of a component and sharingthem with other engineers in a convenient way. Of course, once you’re happy with your design,you’ll want to create the object in real life. CAM is simply the process of taking the designs youcreated using CAD and interfacing with manufacturingmachinery, like circuit board printers or laser cutters, to tell the machine how to actually producethe components you’ve designed. Both CAD and CAM are used everywhere in industry,from designing and manufacturing cars to makingcustom golf putters. NASA engineers are also testing ways touse CAD and CAM to help astronauts on theInternational Space Station. They can use CAD to design tools here on Earth,then send them up to the station to be printedon the 3D printer up there. So even engineers who aren’t strictly computerengineers should be familiar with computers. Programming is also used in a wide range ofengineering disciplines, and the most complex and sophisticatedmachines are often operated, or at leastdesigned, using computers. So, however you choose to apply yourengineering skills, computers are a tool youprobably can’t do without. And with the work being put into computerengineering, the computers of the future willbe even better. Although they might still bug you about softwareupdates.