Most advanced touch screens rely on electrical charge in your skin

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.

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.

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.

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.

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.

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.

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.

Flexible integrated circuits can be built from carbon nanotubes and elastic materials

Stanford researchers arranged the nanotubes in fishnet-like networks that allow deformation without loss of function. The stretchable ICs have been shown to power micro-LED displays and may be used in smart clothing.

Light energy can be transformed into electricity in solar cells via the photovoltaic effect

When light strikes semiconducting material, it can knock electrons out of atoms, creating a charge imbalance within the material. A wire connecting the oppositely charged regions can allow electrons to flow back, balancing the charges and producing an electric current that can be harnessed to power devices.

Tattoos, explained

Tattoos last because immune cells trap ink beneath the skin—but there's more to the story. This overview looks at how ancient cultures used tattoos for status, spirituality and punishment; how technology like the electric tattoo machine transformed the art form, and where innovations like smart tattoos could take it next.

Wireless charging uses a magnetic field to move charged particles in a battery

Based on the concept of electromagnetic induction, when a compatible device is placed on a charging pad with correct alignment, the alternating current flowing through the pad creates a changing magnetic field. This magnetic field induces a current in the device, recharging the battery without a connecting wire.

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.

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.

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.

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.

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

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

Mixed reality devices and other wearables may usurp smartphones

The integration of smartphone features into watches, glasses, and even clothing suggests future technology may be geared toward working independently in the background. Mixed reality technologies are expected to facilitate this ambient computing world by seamlessly and proactively displaying real-time content without physical interactions solely in the real world.

Artificial goose bumps could theoretically be used for information storage

Inspired by how fine hairs stand on the skin with goose bumps, researchers have recently created artificial skin that raises artificial goose bumps when exposed to a laser. This type of precise, localized, and controllable system could potentially fuel later development of programmable machines that could be used for information storage.

Dust particles on Mars can generate lightning

Through triboelectric charging, sand and dust on the Martian surface can become electrified when they rub against one another, causing friction to displace electrons and create charged particles. If this matter forms a strong enough electric field, it can overcome atmospheric insulation and produce electrical discharges, resembling lightning on Earth.

Mechanical watches measure the passage of time via the vibration of a quartz crystal

When electricity from a battery passes through the crystal inside a watch, the crystal vibrates, creating an electrical signal with a precise frequency of one vibration per second. This signal moves the hand of the watch so that it ticks once per second, allowing it to track the passage of time.

Adhesion molecules and intercellular junctions allow cells to connect together

While some organic structures are mostly composed of non-cellular components (e.g., collagen and calcium phosphate minerals in bones), tissues and organs composed of connected cells rely on specialized proteins and connections to create watertight seals that protect cells within the interior from environmental molecules.

What are superconductors?

Superconductors are materials that carry electrical current with exactly zero electrical resistance (move electrons through it without losing energy to heat). Read more about how they work here.

Gradual chemical build-up reduces the effectiveness of rechargeable batteries

During charge cycles, small chemical deposits gradually form a film on the electrodes where they make contact with the electrolyte, trapping ions that would otherwise facilitate the flow of electricity. Mechanical degradation from electrode wear and electrical shorting from structural instability can also reduce battery capacity.

Why there are microchips in credit cards

Credit cards have evolved significantly since their invention in 1950, but security lagged in the US for years. Despite handling only a quarter of global transactions, the US once accounted for half of all credit card fraud. The 2013 Target data breach helped push the adoption of chip cards, reducing fraud but shifting risks to online scams.

The benefits and risks of smart grids, from improved efficiency to cybersecurity risks

By using a network of devices, including digital meters, sensors, and controllers, smart grids can quickly detect mechanical issues and fluctuations in supply and demand, automatically adjusting electricity flow to prevent cascading failures. While this is important for variable solar and wind power generation, many of these computer systems are designed to be controlled remotely, which increases the risk of malicious access.

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.

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

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.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

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

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.

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

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.

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.

Stars appear to twinkle because turbulence in the motion of molecules in Earth's atmosphere causes light to bend and wiggle rapidly on its way to the surface—a phenomenon called scintillation.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Hurricanes, which rely on air consistently spinning in the same direction, cannot cross the equator because air curves in opposite directions north and south of it.

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

The name 'Silicon Valley' arose from the founding of Shockley Semiconductor Laboratory in Fairchild Semiconductor in 1956-57, founded near Stanford University in Palo Alto

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.

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

Netflix profits when you're not watching, and its movies are designed that way—read a detail-rich critical essay exposing lesser-known Netflix takes

Massive 3D printers have been used to build homes by stacking layers of 'concrete toothpaste,' a fire-resistant material that effectively insulates against outside noise.

Dorothy's famous entrance into Oz in 'The Wizard of Oz' relied on analog tricks, including a body double and sepia-toned paint, as much as it did on technology

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.

Memecoins are a type of cryptocurrency—a form of digital currency with a wide variety of uses—created around popular 'memes,' or viral internet jokes.

The price of gas is a composite made up of several different factors, with the federal gas tax making up less than 20% of what drivers pay at the pump.

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

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.