Chikungunya virus vaccine candidates with decreased mutational robustness are attenuated in vivo and have compromised transmissibility. [Vaccines and Antiviral Agents]

IMPORTANCE Chikungunya fever can be just a debilitating disorder which causes severe pain to the joints, which can compromise the patient’s lifestyle for several months and even in some tomb cases lead to death. Within our researchwe developed book live attenuated vaccine candidates against chikungunya virus from applying an innovative genomic layout. When analyzed from the insect and mammalian host, the vaccine candidates failed to lead to disorder, elicited strong protection against further illness and had low chance of reversion to pathogenic phenotypes.

Chikungunya virus (CHIKV) is a reemerged arbovirus, member of their Togaviridae family. It circulates during mosquito vectors chiefly of the Aedes family and a mammalian host. CHIKV causes chikungunya fever, a mild to acute disease characterized by arthralgia, using some fatal effects described. In the past years, several outbreaks mainly due to enhanced adaptation of herpes to the vector and inefficient charge of the contacts between infected mosquito people and also the human host have been reported. Vaccines represent the best solution for its utilization of insect-borne viruses, including CHIKV, but in many cases are unavailable. We built reside attenuated CHIKV by employing a reasonable genomic design centered on various replacements of synonymous codons. In doing so, the virus mutational robustness (capacity to keep phenotype even though debut of mutations to genotype) is diminished, forcing the viral population involving hammering evolutionary trajectories. When tested in the insect and mammalian hosts, we observed entire robust attenuation in both greatly diminished signs of disorder. We also found that the vaccine candidates elicited protective immunity, related to this production of neutralizing antibodies after one dose. During a experimental transmission cycle between mosquitoes and naït mice, vaccine applicants could possibly be transmitted by mosquito sting leading to celiac disease in mice with endangered dissemination. Employing deep sequencing technology we detected an increase in damaging (stop) codons, which affirmed the efficacy of this genomic design. Because the approach involves hundreds of synonymous modifications to the genome, the reversion hazard is significantly reduced, rendering them promising vaccine candidates.

Discovered: How To Eliminate Metal 3D Print Warping

Eliminating warping caused during metal 3D printing [Source: Science Direct]

Researchers have found a way to possibly reduce thermal stress during metal 3D printing.

Thermal stress is perhaps the most unfortunate aspect of metal 3D printing. Caused by the extreme temperatures created by energy sources (usually lasers) to rapidly melt fine metal powder, these temperatures cause all kinds of issues during and after printing.

The problem results from the fact that metals tend to expand and contract while being heated and cooled. Don’t think of this as a “hot or cold” situation. It’s more of the difference in temperature between segments of the print.

The hottest point is always the melt pool, where the laser is currently traversing. That puts the metal at the highest temperature, and it gradually cools down after the laser passes by.

This cooling is quite complex; radiative cooling is affected by surface area. A thin segment might cool more rapidly than a thicker segment. Lower layers are more cooled than higher layers that have been more recently fused. This creates highly complex thermal flows in the print structure.

If not managed, a print could suddenly deform as support structures are sliced off, thus allowing built-up stress caused by thermal effects to release. That’s definitely not good if you’re hoping to print a dimensionally accurate metal part.

Metal 3D Print Thermal Management

To account for this, most metal 3D printing operations feature a squad of engineers to carefully model the thermal flows and then set up the print job to minimize the effect, or at least focus the effects on portions of the print that matter the least.

Now, researchers from Lawrence Livermore National Laboratory (LLNL) have developed a technique that may assist in solving this ongoing issue, in a paper entitled “Reducing residual stress by selective large-area diode surface heating during laser powder bed fusion additive manufacturing”. They explain:

”By illuminating the surface of a build with homogeneously intense, shaped light from a set of laser diodes, the thermal history was controlled thereby reducing the residual stress in as-built parts. 316L stainless steel bridge-shaped parts were built to characterize the effect of in situ annealing on the residual stress. A reduction in the overall residual stress value of up to 90% was realized without altering the as-built grain structure (no grain growth).”

In-Situ Annealing of Metal 3D Prints

Their approach was to simply illuminate the current print layer with laser diodes to rapidly increase the temperature. These operations would typically hit as high as 1000C, after which the temperature would be slowly cooled.

They found that the thermal effects were dramatically reduced by performing this operation during each layer of a metal 3D print job.

This heating process is effectively a type of annealing, a post-processing step often used to increase metal strength on 3D prints. However, the difference here is that it’s done on each layer. The stronger layers thus resist warping much more than normal.

This could be a very promising approach that has so far not been integrated into any known commercial metal 3D printer offering. However, we may soon see this done.

Metal 3D Printing Financial Challenges

I do have one observation, however. An annealing step at each layer, particularly if it includes a lengthy period to cool, could dramatically increase the elapsed time of each print job.

Thus it remains to be seen if this is a financially feasible approach. Large metal 3D printers are quite expensive, and they are made profitable by running them as close to 24/7 as possible, making objects for clients. If the prints take much longer, then that’s a direct hit on revenue from operations.

Via Science Direct

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Physical Demands of Refereeing Rugby Sevens Matches at Different Competitive Levels

Sant’Anna, RT, Roberts, SP, Moore, LJ, and Stokes, KA. Physical demands of refereeing rugby sevens matches at different competitive levels. J Strength Cond Res XX(X): 000–000, 2019—The aim of this study was to compare the physical demands of officiating across different competitive levels in rugby sevens. An observational design was used involving 27 referees (26 men and 1 woman, age: 27 ± 6 years, body mass [mean ± SD]: 78.5 ± 9.3 kg, and height: 179 ± 5 cm). Global Navigation Satellite Systems data were collected across a total of 114 matches during 5 separate rugby sevens tournaments played in England—between May and July 2018—categorized into 4 competitive levels: (a) international, (b) professional, (c) semiprofessional, and (d) amateur. Compared with referees officiating at the international, professional, and semiprofessional levels, referees officiating at the amateur level covered less total (p < 0.001) and relative distance (p < 0.001). In addition, these referees covered more distance walking and jogging (p < 0.001). Amateur referees also completed fewer sprints (p = 0.006), repeated high-intensity efforts (RHIEs) per game (p < 0.001), and spent longer between RHIEs (p = 0.015). Finally, for the amateur referees, the duration of the longest repeated high-intensity bout (i.e., worst case scenario) was lower (p < 0.001), with less distance covered (p < 0.001) and fewer high-intensity accelerations (p < 0.001). Refereeing rugby sevens is therefore more physically demanding at higher competitive levels, particularly in terms of high-intensity efforts. The results provide vital information for practitioners involved in the physical preparation of rugby sevens referees.
Address correspondence to Ricardo T. Sant'Anna,
Copyright © 2019 by the National Strength & Conditioning Association.

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Can transcranial direct current stimulation improve muscle power in individuals with advanced resistance training experience?

The aim of this study was to investigate the effects of transcranial direct current stimulation (tDCS) on countermovement jump performance (CMJ) in men with advanced strength training experience. Ten healthy male subjects, with advanced strength training and squatting exercise experience, were included. Participants took part in an initial visit to the laboratory to complete anthropometric measurements and CMJ kinematic test-retest reliability. Participants then completed three experimental conditions, 48-72 hours apart, in a randomized, double-blinded crossover design: anodal, cathodal and sham tDCS (2 mA for 20 minutes targeting the motor cortex bilaterally). Participants completed three CMJ tests before and after each experimental condition, with one-minute recovery interval between each test. The best CMJ in each moment was selected for analysis. Two-way (condition by moment) repeated measures ANOVA’s were performed for CMJ height, flight time and muscular peak power. Effect sizes and interindividual variability of tDCS responses were also analyzed. There was a significant condition by moment interaction for all outcome measures, with a large pre-post increase in CMJ height, flight time and muscular peak power in the anodal condition. All the participants displayed CMJ performance improvements after the anodal condition. There were no significant differences in both cathodal and sham conditions. Anodal tDCS may be a valuable tool to enhance muscle power related tasks performance, which is extremely relevant for sports that require vertical jumping ability. Anodal tDCS may also be used to support strength training, enhancing its effects on performance-oriented outcome measures.
Corresponding Author: Sérgio Machado , PhD, Programa de Pós Graduação Stricto Sensu em Ciência da Atividade Física da Universidade Salgado de Oliveira, Avenida Marechal Deodoro 263, Centro, Niterói, BRAZIL. CODE: 24030-060, Phone/FAX: 55 21 21394942, E-mail:
Copyright © 2019 by the National Strength & Conditioning Association.

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Alcohol after Resistance Exercise Does not Affect Muscle Power Recovery

The purpose of this study was to investigate the effect of alcohol consumed after heavy eccentric resistance exercise on measures of muscle power. After familiarization and an initial eccentric exercise bout to control for the “repeated-bout effect,” ten recreationally resistance-trained men completed two identical heavy eccentric squat bouts (4 sets of 10 repetitions at 110% of concentric 1-repetition maximum) one week apart. Each exercise bout was followed by ingestion of a beverage containing either alcohol (1.09 g ethanol[BULLET OPERATOR]kg-1 fat-free body mass) or no alcohol (placebo; volume of alcohol replaced with water). Vertical jump (VJ) peak power, VJ peak force, VJ jump height, change-of-direction ability (shuttle run), sprint acceleration (sprint test), and muscle soreness were measured before (PRE), 24 hrs after (24H), and 48 hrs after (48H) each eccentric exercise bout. Although the exercise bout resulted in significantly (p < 0.05) decreased VJ peak power at 24H, significantly decreased VJ jump height at 24H, and significantly increased muscle soreness at 24H and 48H, consuming alcohol after the exercise bout did not affect any of the performance outcome measures. When consumed after a non-novel heavy eccentric resistance exercise bout, alcohol did not affect soreness or recovery of muscular power. Practitioners can use this information to advise their athletes with regards to responsible alcohol use after non-novel exercise. Although short-term anaerobic performance does not appear compromised as a result of acute post-exercise alcohol ingestion, practitioners and athletes should be aware of potential long-term effects of such alcohol use.
Address correspondence to: Jakob L. Vingren, PhD, 1155 Union Circle #310769, Denton TX, 76203; email:; phone: 940-565-3899
Copyright © 2019 by the National Strength & Conditioning Association.

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How To 3D Print Lithophanes

A 3D Printed Lithophane [Source: SolidSmack]

Here’s a history lesson for you:

Back in the 1820s, people used to sculpt pictures onto thin, translucent pieces of porcelain. By varying the cuts and placing a backlight behind the material, a clear image could be viewed. And thus “lithophanes” were born.

But that was almost 200 years ago. Times they have a’changed and so has our technology. Instead of slaving away for days handcrafting a piece of fragile porcelain, today’s lithophanes are made from sturdy(ish) PLA filament plastic and can be crafted in hours using your handy ol‘ 3D printer. Have a gander…

Yep, just like the porcelain lithophanes of old, these 3D printed lithophanes are made possible by, you guessed it, varying the thickness of the printed layers. And now, you can use an ‘Image to Lithopane’ website to upload your images instead of using a chisel, hammer, and a good imagination. It’s all comes together to make it a heck of a lot easier to choose a picture you want ‘etched’ into solid material. Let’s have a closer look, shall we.

Creating a 3D printed lithophane [Source: SolidSmack]

Creating a 3D printed lithophane [Source: SolidSmack]

As Simon Sörensen shows in his video, once you’ve chosen your photo, pick the form on which your picture will be applied. Here it’s important to select vertical printing and a switch the image from a negative to a positive. Unlike the old days, you can preview and adjust what your image will look like. Next, using Simplify3D, you set the orientation, set the infill to 100%, adjust extrusion settings, and lower the print speed to get the best results from the print.

Creating a 3D printed lithophane [Source: SolidSmack]

Creating a 3D printed lithophane [Source: SolidSmack]

After adjusting a few more print settings, Simon starts an 8-hour long print of a smaller lion head photograph. It looks great but, if it looks good small, shouldn’t it look more detailed as a larger print?

Eager to see how far he can push his CR-10 3D printer, Simon does another lithophane print of the same lion head image… this time 170% bigger than the previous print. It takes 46 hours for the lithophane the size of an A4 sheet of paper to complete but the resulting image looks more intimidating than one you’d see on material the size of a postcard.

Read the rest at SolidSmack

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Experiencing XponentialWorks

Avi Reichental at XponentialWorks HQ [Image: Fabbaloo]

I visited XponentialWorks to get inside the story of the “seeding and scaling” company.

Based in Ventura, California, XponentialWorks is the nearly three-year-old brainchild of storied 3D printing entrepreneur Avi Reichental.

He founded the new venture after leaving 3D Systems, where he had been the CEO for more than a decade. At a time when many might have considered stepping back into advisory roles or perhaps even easing toward retirement, Reichental instead took a running leap into another area of business: working with startups and mid-market companies.

He’s not one to sit back and watch, he told me with a smile during one of XponentialWorks’ biweekly happy hours. He needs to be in there, doing. And there’s a lot that needs to be done for the ‘exponential technologies’ the company works with.

What Is XponentialWorks?

There’s still some confusion in general about just what XponentialWorks is: is it an incubator or accelerator? A venture capital company? A parent company? An advisory group? An innovation lab? Simply a coworking space?

“We see ourselves as the seeding and scaling arm for small companies, figuring out how to apply and expand these exponential technologies — drones, automation, 3D printing — to seed and scale and de-risk,” Reichental explained. “In parallel, we help mid-market companies by being their innovation lab.”

These early-stage and mid-market companies coexist in a kind of fostering, innovative cocoon under the XponentialWorks umbrella.

While it might seem a bit zany to house several teams working on pretty different projects — during our walkabout of the various spaces in the business park, we visited teams at work with Apollo Robotics’ drones, NXT Factory’s SLS 3D printers, Nexa3D’s SLA 3D printers, and plugged in with ParaMatters’ generative design software, strolling as well past Nano Dimension’s electronics 3D printer and Techniplas’ varied offerings — it seems to be working. Last spring, Nike acquired the first of the XponentialWorks companies to leave the nest, as Invertex moved its AR over to the shoe giant’s new custom shoe sizing app and in-store offering.

The official explanation for XponentialWorks, per their About Us page, notes:

“XponentialWorks is a venture investment, corporate advisory and product development company, specializing in Artificial Intelligence, digital manufacturing, 3D printing, robotics, and the digital transformation of traditional businesses.”

The current roster of companies under the XponentialWorks umbrella include:

Venture Portfolio:

  • Apollo

  • ParaMatters

  • UNYQ

  • Nexa3D

  • NXT Factory

  • Centaur


  • Blink

Corporate Partners:

  • Sicnova 3D

  • DWS

  • Techniplas

  • Nano Dimension

  • XYZprinting

  • Sharebot

  • Hyperganic

  • EverZinc

Moving Forward

Dedicated Nexa3D lab space [Image: Fabbaloo]

Dedicated Nexa3D lab space [Image: Fabbaloo]

All in all, while the organization is headed by the well-known Reichental, XponentialWorks is anything but a vanity project. Collaboration is the name of the game there, and every partner involved sees that no one technology, no one company will be “the winner” when it comes to Industry 4.0. For additive manufacturing and other next-gen technologies, collaboration is the way ahead — as these teams have consistently emphasized.

I briefly mentioned the happy hour; my first day in Ventura, I was pleased to pop in for the happening, held at the coffee bar in the middle of the office. It’s a popular gathering place, where experienced barista and ace scientist Izhar Medalsy, Nexa3D’s Chief Product Officer, is known to whip up gorgeous coffee drinks. Every couple of weeks, though, it instead houses some wine and hors d’oeuvres for some after-hours conversation where all are welcome, including Cooper, Reichental’s dog. The company culture is very important to the vision, as for teams to work together, it helps for them to know one another.

With both early-stage and mid-market companies working in close proximity, the sharing of knowledge and experience, and familiarity with where to find each, is key to next steps forward.

Market Readiness

The first housings for NXE400 production units [Image: Fabbaloo]

The first housings for NXE400 production units [Image: Fabbaloo]

The focus is on both seeding and scaling, as new and young companies are getting off the ground. At RAPID + TCT this spring, XponentialWorks had its first showing with three ready-for-market products, with ParaMatters’ CogniCAD 2.1, Nexa3D’s NXE400 super-fast SLA 3D printer, and NXT Factory’s debut of its QLS 350 SLS 3D printer.

CogniCAD 2.1 is available now, while the 3D printers are gearing up for full availability. Assembly of the first production systems of the NXE400 begins in earnest next week, starting with about five machines per week, as the design has been finalized and is ready to move full steam ahead. The QLS 350 will, in the next six months, release its is first systems to beta users, then converting these to early adopters and adding to their numbers, ramping up to production in 2020 for first production deliveries.

XponentialWorks, Reichental said, offers venture investment, advisory, and product development expertise. One of the key offerings in all this is the company’s internal structure, as they also offer in-house access to experts in development, PR, IP, HR, and sales. Chief Revenue Officer Michele Marchesan, for instance, was mentioned several times as an invaluable asset in helping all three of these companies.

Such experience is often not immediately accessible for young companies more focused on creating new hardware or software offerings than on getting them into the market.

More To Come

During a full day on-site at XponentialWorks, I appreciated the opportunity to speak at length with Reichental and the Nexa3D, NXTFactory, and ParaMatters teams. There’s more to come from these conversations and tours de technology.

Via XponentialWorks

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Photocentric Liquid Crystal 3D Printers For Industrial Production

Industrial 3D prints made by Photocentric’s LC series of 3D printers [Source: Fabbaloo]

Photocentric continues their journey into 3D printer manufacturing.

The UK-based company is best known as one of the few suppliers of photopolymer resin to the world. Their resins are sold under white label to countless 3D printer manufacturers and materials suppliers, where it is rebranded under various names and sold to clients.

But a few years ago the company decided to begin manufacturing the 3D printers themselves. When we saw their initial machines, they looked promising, although they seemed not particularly distinguished from the rest of the field. However, nowadays that seems to be changing with their release of several new machines and hardware that are quite different.

One of their key differentiating features is the use of “daylight resin”. This refers to the wavelength of light that triggers the polymerization (solidification). Most resin 3D printers use UV light wavelengths, typically 405nm. That’s why you see these 3D printers with transparent orange shrouds: that color filters out stray UV that would corrupt the print.

Photocentric Daylight Resin

Photocentric’s daylight resin allows them to use different light engines for their equipment. Their 460nm resin can be used with many conventional sources of light, and in particular, that means LCD screens.

These are commonly available as they are components of basically every laptop, TV or monitor on the planet. Photocentric is able to re-purpose them as light engines for their 3D printer line, and at relatively low cost.

The advantage is that rather than waiting for a laser to tediously trace the solid portions of each layer, Photocentric’s LCD approach allows an entire layer to be simultaneously illuminated with pixels from the LCD. Thus the printing is quite fast.

While they are able to tailor-make 3D printing solutions of sizes ranging from smartphone-sized LCD panels all the way up to huge “Big TV” sized monitor panels, they do offer a standard line of devices, named “Liquid Crystal”. Their recent machines, unlike the first devices they marketed, are targeted at manufacturing. They’re larger and equipped with features suitable for serial manufacturing.

Their current flagship 3D printer, the LC Magna, offers an enormous 510 x 280 x 350 mm build volume, substantially larger than most other desktop units that often have build volume dimensions under 100mm. The non-stick resin tank, combined with the all-at-once LCD printing approach yields a typical print speed of around 13.3mm per hour regardless of how many objects are being printed.

Production Efficiency With Photocentric 3D Printing

This is one key feature for manufacturing: if you leverage the wide build area, you can produce a lot of small objects in rapid time using this device. Let’s do some arithmetic.

Say your object is 20mm tall, and 40 x 40 mm across. On the LC Magna’s print bed you would be able to fit around 84 units. With that height, the job would complete in 90 minutes. That’s almost one unit per minute, pretty good throughput.

On the other hand, if you attempted to 3D print 84 objects on a resin device with a smaller area, say only 150 x 150 mm, you could fit only 9 units per job! Even at the same print speed of 13.3mm per hour, you would be producing items at about 10X less throughput than the huge LC Magna device.

I think Photocentric understands this concept quite deeply, as they have rushed to produce a follow on device, the Maximus, which will have a build volume of 520 x 510 x 800 mm. At that build volume, their unit production throughput will be that much higher, making the Maximus a very attractive device for industry, even if it is to cost around US$80K when released later this year.

Via Photocentric

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Acute neuromuscular and endocrine responses to two different compound exercises: squat versus deadlift

Anecdotally, it is believed that the deadlift exercise brings about greater levels of central fatigue than other exercises; however no empirical evidence exists to support this view. Additionally, little is known about the acute endocrine response to heavy deadlift exercise and how this may differ to other similar compound exercises. Therefore, the aim of this study was to identify and compare the acute, neuromuscular and endocrine responses to squat and deadlift exercise. Ten resistance trained males completed 8 sets of 2 repetitions at 95 % of one repetition maximum. Maximum voluntary isometric knee extensor force (MVIC), along with measures of central (voluntary activation (VA) and surface electromyography (EMG)) and peripheral (electrically evoked control stimulus) fatigue were made prior to and 5 and 30 min post-exercise. Additionally, salivary testosterone and cortisol were measured at these same time points. MVIC was reduced after the completion of both exercises (p = 0.007) however no difference between exercises was evident. Similarly, although VA changed over time (p = 0.0001) no difference was observed between exercises. As a measure of peripheral fatigue, force from the control stimulus changed over time (p = 0.003) with a greater decrease evident after the squat (p = 0.034). EMG was reduced over time (p = 0.048) but no difference was seen between exercises. No change was seen in testosterone and cortisol. Even though a greater absolute load and larger volume-load was completed for the deadlift, no difference in central fatigue was evident between the two compound exercises. The greater peripheral fatigue observed after squat exercise may be due to the greater work completed by the quadriceps with this exercise. These results suggest that separate periodization, tapering and programming considerations may be unnecessary when using the squat and deadlift to develop muscular strength.
Corresponding author: Matthew J Barnes School of Sport and Exercise Massey University Palmerston North New Zealand Email: Phone: +64 6 3569099 Fax: +64 6 3505781
Copyright © 2019 by the National Strength & Conditioning Association.

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MIT Robot 3D Scans By Gel-Based Touch Sensors

MIT’s experimental 3D scanner uses gel sensors [Source: MIT]

MIT has developed a highly unusual 3D scanning method that relies on touch.

There are plenty of 3D scanning processes available today, including dual or single lasers, LIDAR, structured light and photogrammetry. But it seems that MIT has developed a new approach that’s based on touch.

The key to their project revolves around another technology called “gelsight”. This unusual sensor employs a thin gel layer into which an object is pressed. By using differently colored lights and some machine learning algorithms, the gelsight system is able to capture a 3D scan of the portion of the pressed object.

You can see how sensor this works in this MIT video:

But a cookie-sized sensor is not going to do much in the practical world. That’s where the latest research work has taken place.

The MIT team attached a gelsight sensor to a Kuka robot arm, enabling the sensor to be moved around an object.

Gel Sensor

They developed sophisticated software to interpret the scanned object’s general shape and then used the robotic arm to press the gelsight sensor into all exposed surfaces of the subject. By incrementally adding the gelsight sensor’s findings, they were able to develop a complete 3D model of the entire subject.

One advantage of the touch approach is that the surface texture is captured to an extraordinary degree. This is an aspect that is sometimes not properly done by other 3D scanning processes, in particular photogrammetry, which often results in bumpy surfaces. Not so when touch sensors directly detect the surface texture.

In terms of technology challenges, combining gelsight sensor readings into a 3D model is a well-understood approach. What’s more interesting is programming the robot to understand how to move the sensor around a given object.

In a sense, the robot has to “pre-scan” the subject before actually scanning it by touch. How did the researchers overcome this challenge?

Recognizing 3D Objects

It turns out they simplified the problem by constraining the types of objects that could be scanned. They explain:

“Wenzhen Yuan, a graduate student in mechanical engineering and first author on the paper from Adelson’s group, used confectionary molds to create 400 groups of silicone objects, with 16 objects per group. In each group, the objects had the same shapes but different degrees of hardness, which Yuan measured using a standard industrial scale.

Then she pressed a GelSight sensor against each object manually and recorded how the contact pattern changed over time, essentially producing a short movie for each object. To both standardize the data format and keep the size of the data manageable, she extracted five frames from each movie, evenly spaced in time, which described the deformation of the object that was pressed.”

This dataset was used as input to neural network algorithms that could then provide a rough interpretation of a subject and generate the appropriate motion for the touch scan. However, there are plenty of limitations here, not the least of which is that the robot does not understand object properties like flexibility, weight or fragility.

Nevertheless, this is a very interesting step forward that could result in an ability to capture very detailed surface scans of arbitrary objects — if they find a way to make a more general motion algorithm.

Via MIT Department Of Mechanical Engineering

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