MCADCafe Weekly Review August 7th, 2015

Today, 3D printing is relatively well established, with an ever-increasing selection of printers available, ranging from low-cost personal/desktop 3D units for home to the larger and much more capable industrial-strength printers.

The technology itself has also evolved and is now being implemented in a wide range of industries from automotive to aerospace, construction, health, food, and many others.

By now most of us are familiar with 3D, but for the past couple of years there has been increasing chatter about 4D printing. So what is 4D printing?

A couple of years ago 4D-printing was introduced at a TED Conference in 2013 by Skylar Tibbits, director of MIT’s Self-Assembly Lab.


The Emergence of 4D Printing


He described 4D printed objects as 3D-printed objects that reshape themselves or self-assemble over time, depending on the environment they’re in. In other words, the 4th dimension is time and/or environmental conditions.

Tibbits is said to be working with GEOSyntec to design 4D printed water pipes. As the scale and reach of the technology increases, applications in the military (no surprise here) and construction industries are likely to materialize.

4D Printing


Shapeshifting: 3D printed materials that change shape over time.

Dr Dan Raviv, postdoctoral fellow at MIT, believes that 4D printing may be used in a wide range of applications such as home appliances, childcare products, or even clothes and footwear that optimize their form and function by reacting to changes in the environment.

New York’s Museum of Modern Art (MoMA) recently acquired a 4D-printed dress which designers were able to print using a powder-based nylon material, and made the dress out of thousands of interlocking pieces.

The pace at which 3D printing has evolved in various industries is impressive, but the technology is still too slow for mass manufacturing, and precision and repeatability must still improve for fabrication of structural components.

The power to offer customized products that are manufactured closer to their point of consumption certainly makes the technology appealing to both providers and consumers. It’s a growing market, but there’s still a lot work to be done – particularly around process speed, product size, and the variety of materials that can be used with the technology.

In the near future, 4D printing could be used in space. For example, an improved 3D printing process using materials that could self-assemble (the next topic below) was used to fabricate components on-site and on-demand for astronauts during a space mission.


Self-Assembling 3D Printing

A recent study reported in The Conversation has shown that high frequency vibrations can cause bricks to self-assemble into a larger 3D object, a finding that may one day help reduce the need for factory assembly lines.

The findings, published recently in the journal, Scientific Reports, signal a key advancement in programmable self-assembly, which was previously thought to only be possible using one-dimensional or two-dimensional objects.

Self Assembling 3D print

Self-Assembly Demonstration

The research team, led by Dr Ido Bachelet from the Institute for Nanotechnology and Advanced Materials at Bar-Ilan University in Israel, used an algorithm from the Computational Geometry Algorithm Library (CGAL) as part of a design that allowed 18 tetrahedral bricks to self-assemble into a larger 3D cylinder.

The following video shows blocks in the self-assembly process. Two sets of the object (36 bricks) were inserted in the chamber and after 2.5 hours in a constant speed of 320 rpm one set was assembled. The video doesn’t contain the whole, but portions of it.

The Basic Self-Assembly Process

“Assembly rules are encoded by topographic cues imprinted on brick faces while attraction between bricks is provided by embedded magnets,” the researchers said in their paper. “The bricks can then be mixed in a container and agitated, leading to properly assembled objects at high yields and zero errors.

“Improved designs inspired by our system could lead to successful implementation of self-assembly at the macro-scale, allowing rapid, on-demand fabrication of objects without the need for assembly lines.”

The ability for life to self-assemble is something that continues to puzzle scientists. For example, proteins, viruses, living cells and multi-cellular organisms are all examples of systems in which parts are bonded to each other through attraction to form a structure or pattern.

Hamza Bendemra, a Research Engineer at the Australian National University, who was not involved in the study, said the research of 3D printed assemblies is remarkable.

“The algorithm was inspired by the molecular assembly of the DNA,” he said. But he added that more research was needed to address challenges of time, space and safety for the model to be more efficient at forming and remaining together.

“In the study, a two-brick assembly took less than a minute to self-assemble. However, an 18-piece assembly required over two hours to perform the same feat.”

“The components are subject to high vibrations and collide over and over again until they fit in the right combination. It would be a challenge to implement such a method with materials with low strength and poor impact tolerance without causing damage.”

The next step in developing this concept for construction and manufacturing industries is to use both magnetic forces and adhesives to ensure the assembly stays in place.

Bendemra agreed, saying that “the researchers did a great job at adding topographic cues to ensure a unique combination only would lead to the pieces locking in. Their footage clearly shows that pieces that collide in a non-desired formation detach until they lock-in as planned.”

“The number of pieces involved in the assembly and the nature of the materials being used (including the magnet) in more complex assemblies could limit the use of such a method.”

This self-assembly effort is not entirely unique, as the Self-Assembly Lab is collaborating with Autodesk and Stratasys for 4D printing.

So, there you have it: 4D printing and self-assembly. There is certainly a long way to go to commercial viability, but these demonstrations point the way to some fascinating possibilities.

Article source: Department of Commerce, Economics and Statistics Administration

There is a wealth of evidence that manufacturing jobs are good jobs. But not all manufacturing jobs are created equal. Published data highlight the considerable variation in pay and productivity across manufacturing industries. For example, workers in the computer and electronic product manufacturing industry earn an average of $34 per hour (as of May 2015), while those in apparel manufacturing earn an average of $17 per hour. Now, thanks to a special tabulation of data from the 2011 Annual Survey of Manufactures (ASM) by the Census Bureau, we can also begin examining differences in the highest- and lowest-paying establishments within the same industry.

Our special tabulation of ASM data divides manufacturing establishments in two ways. Industries are first categorized at a detailed level (using 4-digit NAICS codes), and then they are divided into four equally sized groups (or quartiles) by payroll per employee. The resulting tabulations show payroll per employee, value-added per employee and other output and cost measures for each of the quartiles. This division allows us to see how much wage variation there is between the top- and lowest-paying establishments. The payroll data tells us how much, on average, an establishment is paying all of its employees (including line workers, engineers, and administrators).


JoeEngineer Goes 3D
August 5, 2015  by Nic Rady

Recently, I wrote about transforming JoeEngineer from a 2D image into a 3D solid model using SOLIDWORKS with Bringing 2D into the Next Dimension.  Although I can create some very nice rendering using PhotoView 360, I wanted something a bit more tangible and set out to print Joe on a variety of our Stratasys 3D printers to create a life-sized head.

Joe’s Hair – Stratasys 250mc

Joe’s hair was not only the hardest to design, but it was also the most time consuming to print and post process. Important pieces to the hair process puzzle included:

Boeing has had a patent approved for an aircraft engine that employs laser-generated nuclear fusion as a power source, according to a recent story in Business Insider. The controversial idea is generating some attention from organizations, such as Counter Punch.

So, why the controversy?

The patent has generated fears (founded and unfounded) of what could happen if an aircraft containing radioactive fuel were to crash, spreading the fuel across the crash site. All in all, though, an understandable concern.

New Patent From Boeing Reveals That Tiny Nuclear Explosions Will Power Aircraft

The engine works by laser beams focused on a series of deuterium or tritium (radioactive isotopes of hydrogen). The result is a miniature nuclear explosion that “sprays” hydrogen and/or helium through a nozzle, thus creating massive amounts of thrust.

The explosions also create neutrons that bombard an inner wall of the combustion chamber coated with Uranium 238, creating heat that is harnessed by coolant on the other side of the inner wall that runs a turbine and a generator that powers the lasers. This bombardment of the Uranium 238 has an unfortunate side effect of transforming part of it into Uranium 239, a fissile material.

This idea is really nothing new, and is actually derived from an old idea to create a laser-generated fusion rocket for providing relatively quick flights to destinations throughout our solar system, and possibly interstellar voyages. That concept is based on an even older idea called Orion (not to be confused with the NASA spaceship being developed), that would have used the force generated by “small” nuclear bomb explosions to propel spacecraft.

Again, the concept is currently still in the patent stage, and is a long way from becoming a real design, much less a prototype.

Realistically, considering the real danger of using fissile material as fuel, it is highly doubtful that it will ever be used as an aircraft engine.

However, the idea has real merit for propelling spacecraft. These possibilities are especially interesting, given the recently renewed interest in deep space exploration.

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