Scientists shrink 3-D printing so it can work inside cells

3-D printing: The creation of a three-dimensional object with a machine that follows instructions from a computer program. The computer tells the printer where to lay down successive layers of some raw material, which can be plastic, metals, food or even living cells. 3-D printing is also called additive manufacturing.

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells.

cell membrane: A structure that separates the inside of a cell from what is outside of it. Some particles are permitted to pass through the membrane.

dissolve: To turn a solid into a liquid and disperse it into that starting liquid. (For instance, sugar or salt crystals, which are solids, will dissolve into water. Now the crystals are gone and the solution is a fully dispersed mix of the liquid form of the sugar or salt in water.)

DNA: (short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. It is built on a backbone of phosphorus, oxygen, and carbon atoms. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.

focus: (in physics) The point at which rays (of light or heat for example) converge sometimes with the aid of a lens. (In vision, verb, “to focus”) The action a person’s eyes take to adapt to light and distance, enabling them to see objects clearly.

function: The specific role some structure or device plays.

grid: A network of lines that cross each other at regular intervals, forming boxes or rectangles. Or an orderly field of dots that mark where each pair of lines intersect, or cross one another.

journal: (in science) A publication in which scientists share their research findings with experts (and sometimes even the public). Some journals publish papers from all fields of science, technology, engineering and math, while others are specific to a single subject. Peer-reviewed journals are the gold standard: They send all submitted articles to outside experts to be read and critiqued. The goal, here, is to prevent the publication of mistakes, fraud or work that is not novel or convincingly demonstrated.

laser: A device that generates an intense beam of coherent light of a single color. Lasers are used in drilling and cutting, alignment and guidance, in data storage and in surgery.

membrane: A barrier which blocks the passage (or flow through) of some materials depending on their size or other features. Membranes are an integral part of filtration systems. Many serve that same function as the outer covering of cells or organs of a body.

micrometer: (sometimes called a micron) One thousandth of a millimeter, or one millionth of a meter. It’s also equivalent to a few one-hundred-thousandths of an inch.

molecule: A group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in air is made of two bound oxygen atoms (O₂). Water is made of two hydrogen atoms and one oxygen atom (H₂O).

novel: Something that is clever or unusual and new, as in never seen before.

optical physicist: A scientist who studies electromagnetic radiation and how it interacts with matter. Visible light is a form of electromagnetic radiation.

photoresist: A light-sensitive resin that loses its resistance to etching by chemicals. This material is typically used to transfer integrated-circuit patterns onto computer chips as they’re being manufactured.

physicist: A scientist who studies the nature and properties of matter and energy.

subtle: Adjective for something that may be important, but can be hard to see or describe. For instance, the first cellular changes that signal the start of a cancer may be only subtly different — as in small and hard to distinguish from nearby healthy tissues.

toxic: Poisonous or able to harm or kill cells, tissues or whole organisms. The measure of risk posed by such a poison is its toxicity.