How do touchscreens work?

The most common types of touchscreens are capacitive and resistive

Capacitative screens are coated with a conductive material that creates a uniform electric field, which is disrupted by fingers. This disruption is registered by the device across a grid to determine where contact was made. Resistive screens identify touch when fingers push gap-separated sheets into contact with one another.

Most advanced touch screens rely on electrical charge in your skin

Capacitive touch screens store electrical charges in an electrostatic grid of tiny wires. When we touch the screen a tiny electrical charge is transferred from the screen to the finger to complete a circuit (since skin has positive and negative charges). This connection creates a voltage drop on that point of the screen. Cloth, however, doesn't conduct electricity, which is why humans can't wear thick gloves and operate their smartphones.

Efforts to build touch-enabled machines highlight the complexity of human touch

The challenges that engineers are facing as they try to reproduce a human's ability to touch and also give robots the ability to interpret that kind of sensory flow are furthering our understanding of the myriad intricacies of human touch—and the challenges in emulating it.

Immersive technologies include virtual reality, augmented reality, and mixed reality

Virtual reality relies on technologies that use screens to generate every pixel, immersing a user in an entirely digital world. In contrast, augmented reality overlays digital content onto views of the real world. Mixed reality combines both to allow real-time interaction with virtual objects.

Car touchscreen debuted on 1986 Buick Riviera, but flopped

Preceding car infotainment centers by decades, the technology that was unveiled in the Buick elicited praise from auto journalists, but consumers did not make investments in the cars.

SpaceX's Crew Dragon was the first crewed spacecraft piloted by touchscreen

In May 2020, NASA astronauts flying SpaceX's Crew Dragon to the International Space Station used touchscreen controls instead of traditional switches and dials, a significant shift for astronauts and how they pilot and interact with spacecraft. (Some users may experience a paywall.)

A detailed interactive timeline of technology since 1500

Tech devices are heirs to a complex history of both technological invention and social history. What if you could visualize how radio, TVs, and other devices are connected to the past and each other? Trace the elaborate genealogies of your phone and computer with this interactive timeline showing tech inventions since 1500.

A simple explanation of semiconductors

Semiconductor chips are electronic devices that store and process information. Today they can contain billions of microscopic switches on a chip smaller than a fingernail. The article provides a quick overview of how the devices work and how they've provided the backbone of the computer age.

Disney Research developed a haptic interface where you can feel a fireworks display

Disney’s “Feeling Fireworks” uses water jets and a latex screen to replicate fireworks for blind individuals. Such technology may also provide inclusive experiences for the deaf community, though as of 2024, there are no plans to implement them in Disney parks.

Tinder revolutionized dating when it introduced swipe-based interactions

Many dating apps today allow users to "swipe right" to match with someone and "swipe left" to opt out of the match, but Tinder did it first, introducing swipe-based interactions in 2013. The idea for swipes came from the founder's desire to gamify dating—Tinder's early interface was based on a deck of cards that users could sort.

A smartphone contains over a dozen rare earth elements

One of the most important elements is indium, which makes up an electrically-conductive mesh beneath the display that provides touchscreen functionality. Alloys containing REEs are used in the magnets needed for the microphone and speaker.

Watch Steve Jobs introduce the first iPad

Apple's cofounder debuted the first iPad in 2010, framing it as a third category of personal electronics between the laptop and the smartphone. Steve Jobs showed off how thin the device was (for the time) and explained how it was better than smartphones and laptops for browsing the web.

Where did artful screen savers go? A history

Early on in the personal computer days, users and engineers realized screens could be damaged if the same image—of a button, a logo, or a navigation bar—stays static for too long. To preserve the screen, developers deployed screen savers—automatic reductions in the light intensity, or regularly changing patterns on the screen. These artful screen savers had a heyday in the 1990s, but have since lost popularity to the simple black screen. Read the history here.

Explore how cells respond to signals from their environment

In "Dropping Signals," users can drag stimuli, such as hormones and light, into various cellular environments to observe cellular responses. These include changing their shape, enabling the transport of chemicals into or out of the cell via the cell membrane, or dividing to compensate for surrounding damaged cells.

Most TV viewers simultaneously watch a second screen

83% of American TV watchers simultaneously watch a second screen, like a phone, laptop, or tablet. Sometimes that screen might complement what's on the screen (like fantasy football managers watching a game while watching their rosters) but other times it is entirely unconnected.

How do stem cells actually work?

Stem cells are unspecialized cells that can develop into various cell types while also making exact replicas of themselves. This amazing ability has made stem cells a candidate to treat a wide variety of diseases and conditions—though the vast majority of potential therapies remain in the research stage.

Cathode-ray tube televisions are examples of electron accelerators

CRT TVs work by converting electricity into heat, which causes electrons to be emitted from the rear of the device in three beams responsible for the colors red, green, and blue. Electromagnets direct electrons to phosphor molecules on the screen, which emit light and illuminate the pixels.

What are tariffs and how do they work?

Tariffs are taxes on imported goods paid by importing companies but typically passed on to consumers. They vary by country and product and, despite recent spikes, have historically accounted for less than 2% of federal revenue. Explore more with these data visualizations from USAFacts.

A timeline of the science of taste discoveries

The tongue is made up of four types of papillae—elevated, nipple-like projections that give the organ its rough texture. In the early 1900s, initial research into the tongue's varying taste sensitivity led to a misleading map of the tongue and its taste regions. Over the decades, researchers fleshed out five distinct tastes (and more recently, a sixth).

The selfie camera exists thanks to Einstein's discovery of the photoelectric effect

Smartphone cameras utilize sensors such as CMOS or CCD to capture light by converting it into electrical signals through the photoelectric effect. Einstein explained this effect by demonstrating that light behaves as both particles and waves simultaneously, a discovery that earned him the Nobel Prize in physics.

How 5G will transform media and gaming experiences

The latest generation of cellular mobile communication, known as 5G, promises speeds up to 100 times faster than 4G. Intel's Asha Keddy talk to MarketWatch about how this will transform media consumption and gaming experiences.

View maps of seafloor topography, earthquakes, and volcanic activity

Earthquakes and volcanoes are most common at plate boundaries, where moving plates interact. Mapping the locations of these events creates outlines for the different tectonic plates on Earth, whose movements can be tracked via GPS satellites.

Microwave ovens heat food by agitating certain molecules with non-ionizing light

Molecules with resonant frequencies within the microwave range vibrate, producing heat between adjacent matter, just as hands warm when rubbed together. The mesh in front of an oven's door confines the microwaves to the container, while the rotating plate allows different parts of food to travel through regions of maximum vibration.

How do brain scans work?

There’s only one thing in our solar system sophisticated enough to study itself: the human brain. But this self-investigation is challenging because a living brain is shielded by skull, swaddled in tissue, and made up of billions of tiny cells. How do we study living brains without harming their owners? Two experts explain how the various techniques like EEGs, fMRIs, and PETs work in this TedEd talk.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Corrective vision technologies rely on the bending of light waves

When focusing on an object, muscles change the shape of the lens, which refracts incoming light such that it focuses at the retina. If the cornea is unable to bend light correctly, lenses or contact lenses can provide supplemental refraction to ensure a focused image is produced.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

The history of many kitchen appliances involves unexpected discoveries and applications, including wartime radar turned hamster defroster and replacing an 'ice king' with heat-stealing boxes.

When you complete a CAPTCHA on a website to prove you are human, you may be unknowingly training algorithms for self-driving cars, whose systems require training data to help identify crosswalks, bicycles, and other outdoor objects.

Pure water does not conduct electricity because this flow of energy requires the movement of charged particles, and water is a neutral molecule.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

According to the physics of black holes, our 4D reality may be a hologram—a projection of information coded on a 2D surface on the edge of the universe.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Some researchers have labeled nomophobia, the fear of being without your phone, as 'the phobia of the 21st century.'

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Tattoos remain visible on your skin thanks to immune cells called macrophages

In 2019, a laptop loaded with six of the worst malware in history and described as 'an exhibit of historical weaponry' sold for $1.3M.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

Venture capital is a form of funding provided to early-stage companies with high growth potential, typically in exchange for an equity (or ownership) stake

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Some coin denominations have ridges etched on their sides, partly to prevent counterfeiting, in a practice called 'reeding.'

For centuries, Niagara Falls has been a magnet for daredevils seeking to conquer one of nature's most powerful wonders, with its 200-foot drop and water rushing at 32 feet per second with 280 tons of force.