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Solids are generally divided into metals, which conduct electricity, and insulators, which do not. Some oxides straddle this boundary, however: a material's structure and properties suggest it should be a metal, but it sometimes behaves as an insulator. Researchers at the University of California, Santa Barbara are digging into the mechanisms of this transformation and are aiming to harness it for use in novel electronic devices.
Self-assembly is the process by which individual building blocks—at the smallest level, atoms—spontaneously form larger structures. The structures they form depend on the size and shape of the building blocks, and on the conditions to which these building blocks are exposed. This can be demonstrated quite simply using breakfast cereal, or for more complex cases using specially prepared Legos.
We can easily observe light with our eyes, and so it is one of the most familiar parts of the world around us. And yet, light often does amazing and unexpected things. Light travels in straight lines from the source to our eyes. This fact allows us to understand many of the cool things that light can do. In this lesson, we will observe how light creates mirages and shadows. And we will build a pinhole camera which makes things appear upside-down. We can understand the upside-down images by thinking about the straight line that the light took from the object to the screen.
Biophysics is a field that applies knowledge of physics to understand and explain biological phenomena. Biophysicists study life at different levels, from atoms and molecules to cells, organisms, and their environments. They focus on questions such as how proteins function, how nerve cells communicate, how viruses invade human cells, how plants absorb sunlight and convert it into food, and so on. Biophysics has contributed significantly to improving human health in multiple ways, and the study of protein-protein interactions is an especially important biophysical topic. By exploring the molecular basis of complicated biomedical diseases, biophysicists help to develop methods to treat these diseases.
AtomTouch is a free, interactive molecular simulation app, created by researchers at the University of Wisconsin Materials Research Science and Engineering Center (UW MRSEC) to allow learners to explore principles of thermodynamics and molecular dynamics in an tactile, engaging way.
Graphene is a two-dimensional material made from a single sheet of atoms, with outstanding mechanical, electronic, and thermal properties. It is a promising candidate to enable next-generation technologies in a wide range of fields, including electronics, energy, and medicine. This economical, safe, and simple lab activity allows students to make graphene via chemical vapor deposition in 30–45 minutes in a classroom setting.
For the past two decades, giant bubble enthusiasts have been creating soap film bubbles of ever-increasing volumes. As of 2020, the world record for a free-floating soap bubble stands at 96.27 cubic meters, a volume equal to about 25,000 U.S. gallons! For a spherical bubble, this corresponds to a diameter of more than 18 feet and a surface area of over 1,000 square feet. How are such large films created and how do they remain stable? What is the secret to giant bubble juice? Click to find out more!
Very small structures, much smaller than the human eye can see, often fall in the size range of nanometers. By understanding how the molecules that make up these structures interact, we can engineer them to do many special things that cannot be done at a larger scale. One exciting structure is a polymer brush, in which long, chain-like molecules called polymers are tethered at one end to a surface and stick up from the surface like bristles on a hairbrush. Polymer brushes can be used to keep bacteria away, provide an exceptionally smooth surface for items to slide across, or trap other molecules in solution like a hairbrush traps loose hair. In order to engineer polymer brushes that will perform as desired for a given application, we must understand the physics of how the molecular bristles move, and the chemistry of how they interact with their environment.
Neutron radiation detection is an important issue for the space program, satellite communications, and national defense. But since neutrons have no electric charge, they can pass through many kinds of solid objects without stopping. This makes it difficult to build devices to detect them, so we need special materials that can absorb neutrons and leave a measurable signature when they do. Researchers at the University of Nebraska-Lincoln are studying the effects of solar neutron radiation on two types of materials on the International Space Station (ISS), using detectors made of very stable compounds that contain boron-10 and lithium-6.
You’re lining up your phone to take a picture of your dog. Light comes down from the sun, bounces off the dog, and into your camera lens, allowing you to take the photo. Your eyes work similarly, taking in all the light particles, known as photons, that are scattering off of objects in the world. Most things “see” by detecting these bouncing photons, which is why both you and your phone have a hard time seeing anything at all when the lights are off.
Surface tension is a somewhat peculiar force. Its effects are all around us, but since it tends to act at the scale of millimeters or smaller, we don’t always notice it. It’s critical, however, for many creatures smaller than us, from water-walking insects to star-nosed moles that sniff out food underwater. So what is surface tension and where does it come from?
You may know that the media used in magnetic recording technologies, such as computer hard drives, are made of millions of tiny nanomagnets. Each nanomagnet can be switched up or down to record bits of information as ones and zeros. These media are constantly subjected to magnetic fields in order to write, read, and erase information. If you have ever placed a magnet too close to your laptop or cell phone, you know that exposure to an external magnetic field can disrupt information stored this way. Did you know that it is possible for the nanomagnets to "remember" their previous state, if carefully manipulated under specific magnetic field and temperature conditions? Using a kind of memory called topological magnetic memory, scientists have found out how to imprint memory into magnetic thin films by cooling the material under the right conditions.
To increase our use of solar energy, we need to create more efficient, stable, and cost-effective solar cells. What if we could use an inkjet printer to fabricate them? A new type of solar cell uses a class of materials called perovskites, which have a special crystal structure that interacts with light in a way that produces an electric voltage. We've developed a method to produce perovskite thin films using an inket printer, which in the future could pave the way to manufacture solar cells that are surprisingly simple and cheap.
The electric eel's ability to generate incredibly large amounts of electric power from within its body has fascinated scientists for centuries. In fact, some of the world’s first batteries were inspired by studies of this amazing animal. Now, scientists have developed a new eel-inspired energy source that may one day be used to power electronics implanted within the human body.
In most magnetic materials, the magnetic moments of individual atoms are aligned parallel to one another and point in the same direction. In special structures called skyrmions and antiskyrmions, however, they are arranged in a spiraling pattern. Their stability and compact size makes skyrmions and antiskyrmions especially useful for encoding lots of data in a small space. But a few questions need to be answered before skyrmion-based technology can be used in your iPhone or other memory devices. First, why do these magnetic structures form in some materials and not others? How can we design a system where they will form? And how can we generate these structures on demand? Click to find out!