polymer

A sheet of paper left on a wet table warps and lifts its edges. No one controls that motion, but it follows the same laws as plant growth: some areas of the sheet shrink more than others, and the flat form becomes three-dimensional. Engineers have long dreamed of taming this process so that a flat blank folds itself into a desired sculpture. In the new work, that trick succeeded with accuracy down to one percent.

Two ink reservoirs stand on opposite sides of the cell junction. From them, two types of monomers flow onto the membrane, and when they meet, they form viscous droplets of complexes. The droplets barely move, but the free monomers dart around as fast as perfume molecules in a room.

An octopus waits with tentacles spread wide. No central controller directs its arms, but the moment prey touches one, all eight wrap around it. Physicists have recreated a similar trick in the lab with a body that has neither neurons nor muscles: a star polymer with self-propelled arms. The polymer was assembled from small cylindrical vibrobots on a vibrating plate.

Life begins with a bubble. In a warm puddle on ancient Earth, fat molecules could gather into tiny spheres — prototypes of cells. Inside such a sphere, a polymer happened to be present that accelerated the uptake of new fats from the surrounding water. The bubble grew, divided, and passed its composition to offspring.

Hunting for a new material is like cooking without a recipe: you try, try again, and often throw things out. Previously, scientists manually flipped through papers and tested compositions one by one. Now there's a "robot chef" that reads the literature itself, mixes components, and checks what came out.

A raindrop falls on glass and flattens into a pancake. Add a bit of polymer to the water, and it becomes elastic, like jelly. You'd think such a jelly would spread differently.

When an antibody meets a virus, it doesn't latch on with a single death grip. Rather, it's like two bunches of grapes tumbling in water, catching each other with dozens of short tendrils. Each tendril is weak on its own, easily torn by the thermal jitter of water molecules, but together they hold tight.

A bacterial biofilm is like a city made of slime. The houses are the microbes themselves. The streets and bridges are long polymer molecules that bacteria secrete outside. This whole construction is not static: the bridges are constantly breaking and re-forming. The authors built a "toy" computer model of such a city.

A perfume bottle is not just glass with liquid. It is a snapshot of its time, a frozen melody of fragrant notes. From 1900 to 2024, tens of thousands of such 'melodies' have accumulated, and now they can be studied as a single organism.

In a world where Reynolds numbers are minuscule, water turns into thick syrup, and the swimming tricks we know stop working. Here reigns the insidious scallop theorem: reciprocal motions produce no net displacement. Microorganisms found a way out: they grow polymer tails.

The early universe expanded at a breakneck pace: this phase is called inflation. But how exactly did it do it? Some models describe the expansion as a steep exponential surge, others as a more gentle power-law motion.

Membraneless organelles, tiny factories inside the cell, defy conventional rules. Take the nucleolus: here ribosomal RNA is synthesized — long chains woven from carbon sugars, rich in oxygen phosphate groups, and stitched with hydrogen bonds, suspended in the watery environment of the nucleus.

A cell is like a library where thousands of books are copied every day. Molecular machines, polymerases and ribosomes, slide along a template chain and assemble a copy, link by link. These machines have several states: they can slow down, make mistakes, or switch. Previously, calculating such a process took hours.

Finding the right molecule among billions of options is like finding a single grain in a sack of rice. To avoid sifting through everything by hand, chemists increasingly turn to neural networks. But large models require powerful computers, while small ones often lack the big picture. GLACIER tackles this problem like a bright student learning from several mentors at once.

Imagine two immiscible liquids, such as oil and water. Under normal conditions, they tend to separate, forming a clear interface. But introduce microscopic swimmers (bacteria, whose basis is carbon) and the picture changes dramatically.

Magnetic particles are attached to the surface of the diamond by DNA strands, like puppets on strings. They constantly dance under the thermal motion of the liquid molecules. The liquid's viscosity sets the pace: in honey, the particles barely tremble; in alcohol, they dance quickly.

In the first moments of the universe's existence, space was filled with hot plasma, where particles emerged and disappeared like bubbles in a boiling pot. The traces of these processes, stretched to gigantic sizes by expansion, are preserved in the cosmic microwave background — ancient light that has reached us across billions of years.

If you write down a protein recipe on a piece of paper and send it to a print shop, a typo in a single letter can ruin the whole batch.

Long protein threads, their tangled entanglements, and random contacts: this is how the birth of cellular droplets was usually explained. These membrane-less organelles, where important reactions take place, resemble oil drops in water: they arise on their own when molecules separate into phases.

Nitrogen, the very gas we breathe, behaves like a finicky metal under a million atmospheres of pressure. In a diamond anvil cell, it is squeezed to 78–98 gigapascals and heated with a laser to 1800–2500 kelvin. Under these conditions, N₂ molecules rearrange into crystals that can store energy more densely than explosives.

The heart doesn't push blood in a steady stream but in pulses. Each beat sends a wave racing through the arteries, like ripples along a taut garden hose. For a long time, it was thought that an animal's metabolic rate depended only on how vessels branch, like pipes in a house. But new work flips that view: what matters isn't the shape of the pipes but the pulse itself.

In a narrow gap between two plates, water from humid air collects on its own: this is capillary condensation. If the gap is only a few nanometers wide, water no longer behaves like a continuous liquid: every molecule counts.

E. coli is a tiny swimmer in a world where water is as thick as jelly. Inside our gut, it doesn't glide freely but fights through mucus — a tangled web of long molecules, like a ball of knotted threads.

A flexible thread, coiled into a loop, was locked in a tiny box with liquid. It can either absorb water and swell like a sponge, or expel the moisture and shrink into a tight ball. The choice between these states depends on whether the thread has a knot – and which one. The reason lies in entropy, a measure of disorder.

An octopus tentacle bends, grabs, and stretches — all without a single bone. The secret is that inside it, sections that contract alternate with sections that remain passive. Scientists have long tried to replicate this trick in artificial materials, but until now they couldn't precisely dictate how a material would change shape. Now researchers have proposed 3D-printing elastic threads from two materials at once.

Turning light gases like hydrogen and nitrogen into metal is a long-standing dream of physicists. In a new experiment, nitrogen was compressed to 130–140 gigapascals (pressure equivalent to 14 million kilograms pressing on a fingernail) and heated to 3000°C.

Polymers are long threads of carbon and hydrogen atoms. In living cells, they encounter streams of chemical signals that pulse like the surf. Long chains and closed rings behave like skilled surfers: they catch the wave and glide with it. Short fragments and tight coils, counterintuitively, move strictly against it.

When you press your finger on a piece of soft putty, it obediently dents and then slowly returns to its original shape. But if you press on a window pane, it either holds or cracks — no smooth deformation. Both materials are amorphous: their atoms are not arranged in a strict crystal lattice like in metal. Yet they behave completely differently.

Modern batteries with liquid electrolytes can leak or catch fire. Polymer electrolytes (solid, plastic-like materials) solve that problem, but ions move through them more slowly, so the battery loses power. Researchers set up a virtual assembly line: a computer program generated new polymer structures the way a chef experiments with new dough recipes.

A drop of ink in a glass of water spreads out on its own. But if the ink were made of tiny motors, they wouldn't just spread: they'd crawl, jostle, and cluster into swarms. Such self-propelled particles are called active. You can assemble them into molecules like beads on a bracelet. And here's the surprise: the order of beads on the bracelet changes everything.

In the air of factory floors and laboratories, invisible solvent molecules drift. One of them, acetonitrile, has a faint smell, but at high concentrations it can harm health. Typical sensors for it are bulky and expensive, but here we have a thin crystalline film that responds on its own to the presence of vapor.

A water droplet on a fresh polymer film behaves like a guest on new furniture: sometimes it spreads out, sometimes it beads up. This behavior tells you how ready the surface is to repel dirt or, conversely, to hold paint. Previously, such tests were done by hand, one film at a time. Now there's a robot called PANDA-film.

Two voices in a molecular duet can sound in unison or cancel each other into silence. In physics, such silence is called a dark state: a quantum excitation that does not interact with light and therefore lives unusually long.

Six barium ions lined up in a flat hexagon inside a Paul trap, a device that holds charged particles with oscillating electric fields. But a slight change in the shape of the trapping potential made the crystal rearrange: one ion moved to the center, and the other five formed a ring around it.