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.

Electromagnetic repulsion prevents objects from making contact with one another

The feeling of touching something is a sensation caused by the electromagnetic force between the electrons on the surface of objects. Since this force grows to infinity with proximity, no two surfaces can ever achieve matter-to-matter contact.

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.

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.

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.

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.

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.

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.

Sound can shatter glass if its frequency matches the material's natural vibrations

The sound made by an object when struck is its resonant frequency, which is the sound made when energy is dissipated. Providing energy at that frequency amplifies the vibrations, rather than allowing them to dissipate, which can deteriorate the object's structural integrity.

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

That’s a sharp increase from the 75% who thought tipping culture had gone too far in 2024. One potential culprit? The proliferation of tipping screens in places outside sit-down restaurants, such as coffee shops and hair salon. Three in 10 Americans say they give less when presented with tipping screens.

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.

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.

View the three types of coral reefs, categorized by where they form

Fringing reefs—the most common type—are built from coral depositing calcium carbonate onto the seafloor closest to the shoreline. Barrier reefs grow further from and parallel to the shore, while atolls are the result of mid-ocean volcanoes or seamounts eroding away and leaving a lagoon surrounded by reefs.

Tennis can be played on clay, grass, hard court, or carpet

Tennis started on grass surfaces in England, but as the sport has grown, so have the surfaces used to play the game. This article details how each surface affects ball speed, bounce height, and player movement, and highlights which Major championship uses which surface.

Visualizing a stroke at the microscopic level

By far the most common type of stroke is what is known as an ischemic stroke. This occurs due to either an embolus (a blood clot that travels to the brain from elsewhere in the body) or a thrombus (a blockage that forms within the brain itself).

Receptors on the cell surface are key to whether a virus is successful

Viral receptors are key regulators of host range, tissue tropism, and viral pathogenesis—basically, the door locks on cells allowing viruses to invade, if they have the right key. How this process works at the microscopic level determines whether a virus is able to trigger a widespread illness in the host.

There are three types of stem cells, each with different properties

Embryonic stem cells are "blank slates" that can change into any other type of cell. Adult stem cells can become specialized cells to replenish the supply or repair injury, while induced pluripotent cells are "reset" by scientists and used in clinical and medical applications.

Mineral and chemical sunscreens protect differently but both guard against UV damage

UVA rays age the skin, while UVB rays are more directly linked to skin cancer. Mineral sunscreens, with ingredients like zinc oxide, physically block rays, while chemical ones absorb UV and turn it into heat.

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

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.

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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.

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.

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Objects can be 3D printed with light by projecting 2D computerized tomography (CT) scans onto rotating cylinders of resin, which solidify upon exposure.

Dirty lightning is a thunderstorm created from friction between rising and falling flows of ash and smoke during volcanic eruptions.

Firework or sparkler burns, even if they cover a relatively small area of skin, can significantly affect our range of motion.

Some renewable energy sources may weaken the resiliency of electric grids by removing outage buffers provided by coal- and natural gas-fired plants, which provide the system with more time to find a new power source if a plant goes down.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

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

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

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Scientists have struggled to pin down Ebola's natural reservoir species for decades, but the available evidence suggests that it's very likely fruit and insect-eating bats found in Africa.

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Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

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