The most common types of touchscreens are capacitive and resistive

How do touchscreens work?

Touchscreens have revolutionized digital interactions, but how they work widely varies depending on the device. Explore the history and workings of the most common types—capacitive and resistive—and new interaction methods incorporated into foldable screens and touchless interfaces.

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.

When humans perceive touch, the information is sent to the thalamus and then to the primary somatosensory cortex, the part of the brain that receives sensory input.

You have never made physical contact with anything in your life because electrons in the outer layer of atoms on the surface of objects repel one another.

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.

Touch is the first sense a fetus develops in the womb

During gestation, our sense of touch begins to develop around 8 weeks, starting with the development of sensory receptors in the face and, about a month later, in the palms and soles of the feet.

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.

Shorter, more frequent touches are better than longer, rarer ones

That's according to a 2024 meta-analysis of 137 studies on touch. It found that as long as the touch is consensual, the identity of the toucher mattered little for adults, and there was even a benefit to receiving "touch" from objects like weighted blankets or robots. For newborns, however, the identity of the toucher did matter, and the greatest benefit came from parental touch.

We can sense touch even through a tool

Research published in 2019 indicates that the same brain regions involved in sensing touch on the body also process it when humans use a tool to do the touching. Essentially, it's acting as a sensory extension of the body. (Some users may experience a paywall.)

The most common type of 3D printer fabricates objects using plastic

At the consumer level, the most common printing method is fused deposition modeling, which builds objects by melting an extruding thermoplastic filament that is deposited in layers. For industrial applications, selective laser sintering, which uses a laser to fuse particles of polymer powder (e.g., nylon), is preferred.

Friction is the force that resists the sliding of surfaces along one another

Friction always acts to resist movement and is determined by how rough the surfaces are and how hard they are pressed together. In the case of fluids, friction arises from the relative motion between adjacent fluid layers, which act like sliding surfaces.

Integrated circuits come in digital, analog, or mixed types

Each type can be further divided based on application, technology, and integration level. Digital ICs are used in computer memories and microprocessors, while analog ICs process continuous signals within sensors, including temperature, light, and sound.

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.)

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.

View the various types of lightning

The most common form of lightning involves channels of electricity between oppositely charged regions within a cloud or between two clouds to reestablish electrostatic equilibrium. While cloud-to-ground lightning is understood best, research is ongoing to fully model the mechanisms behind rarer forms of lightning, such as transient luminous events.

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.

A Venus flytrap's hairs convert sensory touch into electrical signals

A stretch-activated ion channel called DmMSL10 acts as an amplifier, converting grazing contact into a strong impulse that the plant uses to react and close its jaw. To distinguish prey from raindrops or other stimuli, the jaw only closes when the hairs are touched twice in quick succession.

Simulate the buildup and discharge of static electricity through friction by dragging the arm and leg of 'John Travoltage' along surfaces.

How texture affects taste

Texture is the brain's interpretation of several sensations, including pressure, as registered by our teeth, tongue, and finger tips, and sound, as recorded by our ears. Texture also speaks to food particle sizes—smaller than 35 microns contributes to the sensation of creamy—and the balance between flavor and mouth time, such as the crunch of a crispy chip or the bounce of a chewy caramel.

While charges consistently move in the same direction in a direct current, the flow of charges changes multiple times per second in an alternating current.

Metal detectors identify induced magnetic fields in conductive objects

A changing magnetic field in a transmitter coil causes an electric current to be produced in materials that conduct electricity. This current generates its own magnetic field, which can be detected by a receiver coil and transmitted to a control box, which identifies the presence and depth of an object.

Blindfolded people could identify objects by touch alone a week after encountering them

These touch memories are more complex and durable than previously thought. In research published in 2018, blindfolded volunteers touched over 150 household objects for about 10 seconds each, and afterward correctly identified the objects more than 90 percent of the time when presented with the object and a similar one. Participants still knew most of the objects a week later with about 85 percent accuracy. (Some users may experience a paywall.)

Humans likely cannot tickle themselves because there's no element of surprise

Unraveling the neural mechanisms of tickling—formally called gargalesis—is an area of active research, but a leading theory about why we can't tickle ourselves is that the brain's somatosensory cortex processes self-touch differently than it does external touch. The cerebellum already anticipated what was going to happen when you move your hand for self-touch, limiting the effectiveness of a self-tickle.

Brain-reading devices are helping paralyzed people control prosthetics that restore a sense of touch.

Octopuses have taste receptors along their tentacles

Octopus suction cups are filled with modified sensory receptors that can bind with a greater variety of materials and transport a wider array of information, such as flavor, from tactile stimuli. These structures allow the animal to search for food as it crawls the ocean floor.

73% of people report they crave more physical touch in their lives

This figure came from a 2019 survey of 110 adults and examined what's formally called a "touch gap." Touch helps reduce stress, strengthening our immune system, and overall well-being. It can also improve children's health, adjustment, and IQ scores.

In the photovoltaic effect, light generates electricity by creating a charge imbalance after knocking electrons out of atoms in the semiconducting materials of solar cells.

A researcher thinks she knows why people keep touching museum exhibits

A museologist who studied unauthorized touch at the British Museum concluded that people may feel it's difficult to learn about things "unless you handle them" and that people are trying to connect with the past, viscerally. Her work has included interviewing British Museum visitors who committed unauthorized touches and spending extensive periods observing people touching prohibited items across 2004 and 2005.

While dry surfaces slip on ice, warm or moist ones may stick to it as moisture quickly freezes onto the ice.

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.

Each taste bud has 10 to 50 sensory cells that form a flower-like capsule

At the top of the structure are thin filaments known as "taste hairs" that bind taste-producing substances to the surfaces of the cell, after which corresponding electrical signals are sent to the brain. Adults have 2,000 to 4,000 taste buds on their tongue.

Simulations suggest ice's slipperiness comes from rearranging molecules

Past models have proposed that slipperiness arises from a thin layer of liquid water formed at the ice's surface by frictional melting. However, new research suggests that electromagnetic forces between interacting surfaces push water molecules out of an ordered, crystalline structure and into a shapeless, soft, slippery layer. This process occurs solely through contact, independent of pressure or friction.

Earth’s major tectonic plates make up 95% of its surface

Tectonic plates are pieces of Earth’s lithosphere, which consists of the crust and the solid, upper layer of the mantle. Segments of major plates can break and form minor or microplates, whose total number varies based on ongoing geological activity.

Catfish have taste buds spread across their entire skin, making their whole body function like a tongue that can taste food several feet away.

How brain cells carry information

At any moment, there is an electrical storm coursing through your body. Discover how chemical reactions create an electric current that drives our responses to everything from hot pans to a mother’s caress.

View maps of seafloor topography, earthquakes, and volcanic activity, which scientists use to create outlines of Earth's tectonic plates.

Transistors are the foundational components of integrated circuits and microchips and manage the processing of electronic signals by controlling the flow of electricity.

Debating whether water is or is not wet depends on one's definition of wetness

If defined as a liquid sticking to a surface, then water itself is not wet. The sensation of "wetness" arises from water molecules latching onto an object. This occurs because water is a polar molecule possessing local regions of positive and negative charge that are attracted to charge imbalances on the surface of materials.

The applications and industrial uses of graphene, the single-atom-thick material

Shortly after its discovery in 2004, the strength, flexibility, optical properties, and conductivity of this thin layer of carbon atoms earned it the designation of a "wonder material," but breakthroughs in its use have taken decades of research. As of 2026, graphene-enhanced electronic sensors, optical microchips, concrete, and supercapacitors are available, though scale production challenges remain.

The iPhone's impact in 10 charts

It's been almost 20 years since Steve Jobs first unveiled the iPhone, the device that would come to define Apple for years and change not just the smartphone industry but the world at large. 10 examples of the iPhone's impact include its all-screen touch interface and the way it led to the rise of app culture.

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.

The virtual reality era has finally arrived

The smartphone era has driven a large share of the consumer electronics market for almost 20 years now. But what comes next? Dominant computing platforms come and go over time, and there’s reason to believe that mixed reality devices like headsets and glasses might be the form factor that eventually replaces smartphones. This article presents a snapshot of where we are right now in the VR era, and what the future holds.

Nearly 9 in 10 Americans were annoyed by tipping as of 2025.

Solar power is converting the sun's energy into thermal or electrical energy

Solar energy is the most abundant renewable energy resource. It can be captured in photovoltaic cells to generate electricity, solar heating and cooling technologies for temperature control, and concentrated solar power to drive steam turbines.

Electrogenic animals generate their own electricity within an electric organ by changing the pattern of electrical charges in disc-shaped cells called electrocytes.

Semiconductor chips are electronic devices that store and process information

They can contain billions of microscopic switches on a chip smaller than a fingernail. An article provides a quick overview of how the devices work and how they’ve provided the backbone of the computer age.

A web of sensory neurons in the skin help filter out background sensations

The somatosensory system helps us organize and navigate our surroundings, enabling us to understand our bodies in relation to our environment and also filter out minor sensations that are basically background noise so they aren't overwhelming to our bodies. Meanwhile, viscerosensation—or internal sensation—refers to the internal sensory neuron system that conveys information from internal organs to the brain.

Water vapor is used to manage heat in high-end smartphones

While smartphones have traditionally been cooled using a highly conductive plate that dissipates heat from the chip, vapor chambers offer a higher heat-removal capacity. This technology has been utilized in laptops for decades to absorb heat by cycling a fluid between liquid and gaseous phases.

When struck, objects vibrate at unique rates called resonant frequencies, which makes tapping wood sound different from tapping metal, but providing objects with sound at their resonant frequency can cause them to shatter.