A new synthetic material that creates a linked sensory network similar to a biological nervous system would enable robots to sense how they interact with their environment and adjust their actions accordingly. Robots fitted with the material, developed by Cornell University Ph.D. student Patricia Xu through the Organic Robotics Lab, would be well suited for manufacturing and the health care industry.
“We want to have a way to measure stresses and strains for highly deformable objects, and we want to do it using the hardware itself, not vision,” said lab director Rob Shepherd, associate professor of mechanical and aerospace engineering and the senior author of the lab’s paper, “Optical Lace for Synthetic Afferent Neural Networks,” (Science Robotics, September 11, 2019). “A good way to think about it is from a biological perspective. A person can still feel their environment with their eyes closed, because they have sensors in their fingers that deform when their finger deforms. Robots can’t do that right now.”
Shepherd’s lab previously created sensory foams that used optical fibers to detect such deformations. For the optical lace project, Xu used a flexible, porous lattice structure manufactured from 3D-printed polyurethane; she threaded its core with stretchable optical fibers containing more than a dozen mechanosensors, then attached an LED light to illuminate the fiber.
When she pressed the lattice structure at various points, the sensors were able to pinpoint changes in the photon flow. “When the structure deforms, you have contact between the input line and the output lines, and the light jumps into these output loops in the structure, so you can tell where the contact is happening,” Xu said. “The intensity of this determines the intensity of the deformation itself.”
The optical lace, which also is washable, would not be used as a skin coating for robots, Shepherd said, it would be more like the flesh itself. A robot would need to know its own shape in order to touch and hold and assist in manufacturing without damaging parts or product. “If they can feel what they’re touching, then that will improve their accuracy,” Shepherd said.
While the optical lace does not have as much sensitivity as, say, a human fingertip that is jam-packed with nerve receptors, the material is more sensitive to touch than is the human back.
The researchers also plan to explore the potential of incorporating machine learning to detect more complex deformations, like bending and twisting. “I make models to calculate where the structure is being touched, and how much is being touched,” Xu said. “But in the future, when you have 30 times more sensors and they’re spread randomly throughout, that will be a lot harder to do. Machine learning will do it much faster.”
Even as robots become more aware of how they interact with the environment, humans still have a distinct advantage. “We don’t know our own bodies as well as some robots know parts of their limbs and joints and fingers,” Shepherd said. “But we can still perform better than robots generally because we can deal with uncertainty through mechanical design, as well as neural architecture.”
The paper was co-authored by postdoctoral researcher Anand Kumar Mishra; students Lillia Bai and Cameron Aubin; and Letizia Zullo from the Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia. The research was supported by grants from the Air Force Office of Scientific Research and the National Institutes of Health.
Source: Cornell University
Chocolate Clouds THC Testing
Chocolate components may interfere with cannabis potency testing, causing inaccurate results.
Manufacturers add cannabis to a wide variety of foods, and the composition of these products, (the matrix) can affect potency testing results. In an investigation focused on potency testing for cannabis-infused chocolates, David Dawson, the project’s principal investigator, and his colleagues at CW Analytical Laboratories noticed some “weird potency variations” depending on how the chocolate samples were prepared for testing.
So the team decided to study the effects of altering sample prep conditions, such as the amounts of chocolate and solvent, pH, and type of chocolate, on the concentration of ?9-tetrahydrocannabinol (?9-THC), the major psychoactive constituent of cannabis, measured by high-performance liquid chromatography (HPLC).
“When we had less cannabis-infused chocolate in the sample vial, say one gram, we got higher THC potencies and more precise values than when we had two grams of the same infused chocolate in the vial,” Dawson said.
Not only does this go against what he would consider to be basic statistical representation of samples, where one would assume that the more sample you have, the more representative it is of the whole, but, he said, “Simply changing how much sample is in the vial could determine whether a sample passes or fails, which could have a huge impact on the producer of the chocolate bars, as well as the customer who might be under- or overdosing because of this weird quirk of matrix effects.”
It also has critical regulatory implications. “If an edible cannabis product tests 10% below the amount on the label, California law states that is must be relabeled, with considerable time and expense,” Dawson said. “But it’s even worse if a product tests 10% or more above the labeled amount — then the entire batch must be destroyed.”
The results suggested that some other component of the chocolate — a matrix effect — was suppressing the signal for ?9-THC. So Dawson is trying to figure out which ingredient of chocolate is responsible for the matrix effects. He has tried spiking a standard solution of ?9-THC with varying amounts of chocolate bar, cocoa powder, baker’s chocolate, and white chocolate, all of which have different components, and observing how the HPLC signal changes. “Our best lead right now is that it has something to do with the fats, which makes sense considering that ?9-THC is fat-soluble,” Dawson says.
The team would like to extend their analyses to other cannabinoids, such as CBD, and they plan to investigate other food matrices, such as chocolate chip cookies. Dawson said he hopes the research will contribute toward developing standard methods for cannabis potency testing in a variety of edibles.
The research was presented at the American Chemical Society (ACS) Fall 2019 National Meeting & Exposition.
Source: American Chemical Society (ACS)
From Plastic to 3D Ink
A Russian University student develops a way to turn plastic waste into 3D ink.
Gokma Sahat Tua, a bachelor’s student at Tomsk State University (TSU) in Siberia, Russia, has developed a way to recycle plastic waste into ink for 3D printing. The student from Indonesia developed his project as part of the curriculum of TSU and the University of Maastricht in The Netherlands.
The TSU Tomsk International Science Program (TISP) is an international bachelor’s degree program in the natural sciences, physics, and mathematics areas presented in English, developed jointly with the University of Maastricht. The program is problem-practice oriented, that is, it involves students in solving real problems. One of these was undertaken by Tua.
“We have developed an extruder for recycling plastic waste into 3D printing ink,” Tua explained. “The machine is assembled in parts, which can be ordered online. The total cost will not exceed 10,000 rubles ($155 U.S.). That is, this is very cheap equipment that a group of students can afford.”
The extruder utilizes raw plastic material that is not accepted even for standard processing. “If you don’t go into technical specifications, the extruder transforms polyethylene and other types of plastic into 3D printing materials,” he said. “You load the resulting thread into a printer and can print anything — watches, chairs, or any designer items and models.”
Currently, the project team has developed a website with information on waste recycling, its standards, and the possibilities for the second life of plastic. A mobile application also is planned. “From an environmental point of view, plastic is a dangerous, toxic, and useless material with a specific odor,” Tua said. “But for design, it is a supermaterial that can be used everywhere and saves money.”Source: Tomsk State University