Read Online Janine Marie - Rigging a Murder 01 - The Single Shoe Mystery by Janine Marie - Free Book Online Page A

work with an additive process, where an object is created by laying down successive layers of material.
    “What is 3D printing exactly?” Katie asked, clearly confused. “3D printing is a process of making three-dimensional solid objects from a digital model. An example for you might be making a clay pinch pot. I know you like to make things with clay, correct?”
    “Yes, I made Mom a pinch pot last year and she keeps her favorite earrings in it.”
    “Right. First, let’s say you drew out a detailed picture of the exact pot you wanted. Our products are made from digital drawings or complex computer code, …. Then you would make your pinch pot by taking a ball of clay, working with it until you could stick your thumbs in the middle and pull up the sides to make a bowl.” Here Thomas looked at Katie for her nod of both agreement and that she was still listening and following.
    “That is called a subtractive process in traditional manufacturing techniques, which mostly rely on the removal of material by drilling, cutting, or in the case of a pinch pot using your thumbs and a wheel to pull at the clay and make your shape.
    “Our 3D printing machines make products by building them up instead—more like making a coil pot. For a coil pot you roll the clay between your hands until you make long coils, then you stack the coils one on top of the other until you have made the shape of a bowl. That’s exactly what our 3D printing machines do, but we make plastic and metal components. We’re a long way from being able to crack eggs, mix in liquids and flour and other dry ingredients, then cook them. That said, we just incorporated phase-change memory chips into our machines, and who knows where that might lead in the future?”
    “What is phase-change memory?” I asked, intrigued. I had never heard of it before.
    “Phase-change memory is a type of non-volatile random-access memory that—”
    “I’m leaving now,” interrupted Katie as she disappeared down into the boat, her window wiping completed.
    Laughing, I said, “Either she has gone to make a pinch pot, watch a movie, or both. Now tell me about this memory, and why is it important?”
    “Well, phase-change memory chips are both faster and more durable than traditional flash memory. What’s really exciting is it can retain information even when the power is switched off.”
    “How does it do that?”
    “Phase-change memory chips rely on a glass-like material called chalcogenides.” Noting my confused expression, he continued, “Chalcogenides is, as I said, a glass-like material typically made of a mixture of germanium, antimony, and tellurium.”
    “Okay, and why is this special glass so great?”
    “This glass can switch between two states: crystalline and amorphous. The amorphous state is a disorderly state; think of the amorphous state being binary code ‘0,’ compared to a crystalline or orderly state with a binary number ‘1’. Chalcogenides can do this switch very quickly when an electrical current causes one of the electrodes on either side of the chalcogenides to heat up, thus causing the chalcogenides to melt to an amorphous or disorderly state, and as it cools again if forms a crystalline structure or orderly state.”
    “That’s very cool, but why is it better than traditional flash memory?” I asked, trying to visualize this glass-like structure changing from a solid to liquid form quickly, still unclear how that holds memory.
    “Writing to individual flash-memory cells involves erasing the entire region of neighboring cells first. This is not necessary with phase-change memory, which makes it much faster. In fact, some prototype phase-change memory devices can store and retrieve data a hundred times faster than flash memory.”
    Deciding that the conversation was getting a bit technical, I asked, “So how does this new memory chip help your 3D printing machines?”
    “Our machines are currently controlled from a laptop or computer.