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3D-printed Millimeter-sized Robots April 25, 2019

Posted by stuffilikenet in Uncategorized.
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An exciting (and lovingly detailed) paper in Science Robotics documents the design and production of Millimeter-scale flexible robots with programmable three-dimensional magnetization and motions for use in hard-to-reach body parts and possibly surgery as well. Developed by researchers in the University of Toronto, the tiny little device is activated by a magnetic field:

As in all the best papers, this one show materials and methods in exquisite detail, illustrating the physical apparatus for patterning the magnetic needles which make up the basic structure of several tiny machines: the millimeter-scale segmented magnetic swimmer, the untethered multi-arm magnetic microgripper, and the multi-legged paddle-crawling robot.

What’s really wonderful about this paper is the careful explanation of the first principles used to build up all the other pieces (see Table 1., where they show the reason they are able to successfully manipulate in three dimensions using only a single magnetic field).

Table 1. Capabilities of major existing methods to pattern magnetic particles. 1D: Only binary magnetization can be patterned, e.g., longitudinal or perpendicular recording in a hard disk drive. 2D: Direction of magnetization in each layer is restricted to a single plane. 3D: Magnetization in each layer can be patterned in arbitrary direction. Discrete: Magnetization in each area is independent of adjacent areas. Continuum: Magnetization in each area cannot have sudden changes with respect to adjacent areas. N/A, not applicable.

Screen Shot 2019-04-25 at 10.10.00 AM
*Shape of media refers to the structure of the composite materials in which the magnetic particles are dispersed. 2D refers to planar structures, whereas 3D refers to solid 3D structures.

†States of magnetization is defined as degrees of freedom related to the orientation of hard magnetic particles or preferred magnetic axes of soft magnetic particles in each area.

 

Beautiful. The rest of the paper is just as detailed, and even fairly easy to understand.

 

Homework: T. Xu el al., “Millimeter-Scale Flexible Robots with Programmable Three-Dimensional Magnetization and Motions,” Science Robotics (2019). robotics.sciencemag.org/lookup … /scirobotics.aav4494

Eifelheim, by Michael Flynn April 15, 2019

Posted by stuffilikenet in Awesome, Books, Brilliant words.
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Eifelheim, by  Michael Flynn, is a wonderful book full of historical accuracies, plausibly. Human characters, utterly fanciful science fiction and (in the audiobook version) droll and dry remarks from demons (in the 13th century) or aliens (in the 21st). In both eras, the story is fascinating as we see into the mind of a medieval village priest and two modern-day historians.  The story is told by both, without the usual historical whiplash which usually accompanies this sort of perspective switch.  The medieval setting lends a certain claustrophobic cloud of uncertainty to the actions of the parish priests, who succors aliens and finally allows them to live in his parish.  It is one of those rare books where Christian charity is given a fair shake, even while the foibles and failures of human beings undermine the whole religious structure.

A very good read and I recommend it most highly.  The audiobook is available at Amazon (of course), but also at sfpl.org.

EXCITING UPDATE: I liked Flynn’s writing so well I started January Dancer, which I also recommend for wordplay alone. Possible review coming up, but I’m pretty sure it will be flattering.

Semiosis, by Sue Burke April 10, 2019

Posted by stuffilikenet in Books, Brilliant words.
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Semiosis, by Sue Burke is a lovely tale of space colonists dedicated to living in harmony with Nature.

Nature has some ideas about that, however.

Specifically, the plants on the colonists’ new world are intelligent in varying degrees, depending on size, longevity and, uh, temperament (sort of like humans).  The interaction of humans with their new acquaintances forms the whole of the book, and especially the humans interacting with each other in response.  It’s a complex, multigenerational tale and has some wonderful and horrible things like dictatorship enforced by lies, murder and rape (fertile females being too valuable to a small colony to kill outright), war with another race of space colonists, psychopathy and madness and gratuitous democracy.  It’s well told and competently read by Caitlin Davies (the female narrator), Daniel Thomas May (male narrator) in about equal parts, as they tell the story from the point of view of several different characters, including a perspicacious bamboo plant.

The very best of this is, of course, the idea of a sentient plant (plants, really; there are several intelligent species in the story) and the thoughts and feelings they express…and do not express.

A must read for science fiction readers, I recommend this one highly. Available at Amazon and sfpl.org.