The fourth dimension to 3D printing

http://www.extremetech.com/extreme/206368-adding-the-fourth-dimension-to-3d-printing

Adding the fourth dimension to 3D printing

As 3D printing continues to revolutionize manufacturing, researchers have decided that three dimensions are not enough, and so the concept of 4D printing has begun to emerge. These four-dimensional objects are still built layer by layer in a 3D printer. But given time – the fourth dimension – these devices can automatically morph into a different shape, and thereby even change their function.

So far, researchers have developed devices using materials that are actuated by water or heat. This is significant, since the structures are ready as soon as you pick them up from the printer. However, up until now, the prototypes developed were slow, severely limited in the amount of times they could be used, and weak, since they relied on a bending motion in a flexible material.

Professor Marc in het Panhuis and PhD student Shannon Bakarich are set to change all that. The University of Wollongong researchers are the first to use a process whereby four different materials were printed simultaneously. The hydrogels used by the team consist of a network of poly N-isopropylacrylamide (PNIPAAm) and alginate. Alginate is a salt of alginic acid that is commonly found in seaweed and algae. Among other things, it is used as a thickener in food. PNIPAAm consists of two polymer networks entangled in one another. This gives the material strength and durability. When cracks form in one network, the other network bridges the gaps and so prevents greater damage.

4D printing 3D printing

The dual-network structure is not unique to PNIPAAm. However, the researchers used PNIPAAm since it exhibits a large change in volume at a critical temperature of about 32-35° Celsius (90-95° F). This change in volume is caused by a transition of the polymers from a collapsed globule state to an expanded coil state. When the temperature goes down, the polymers collapse back into globules.

The researchers combined thin sections of PNIPAAm with traditional materials. This allowed them to create a design capable of relatively fast linear motion, much like the contraction of a muscle. Best of all, this process is reversible. The transition can be actuated by different stimuli, depending on the hydrogels used.

Using PNIAAm, the researchers have developed a functioning valve that responds to the temperature of the water surrounding it. “It’s an autonomous valve,” says Panhuis in a statement. “There’s no input necessary other than water.” An autonomous device like this is valuable in medical soft robotics. As soon as the surrounding water reaches a certain temperature, the polymer strands inside the hydrogel change their shape. The large change in volume in the hydrogel causes a strong linear motion, which closes the valve.

Combining smart materials and 3D printing in this way offers an exciting method of creating custom designs of small autonomous devices. “The cool thing about it is, it’s a working, functioning device that you just pick up from the printer,” Panhuis said. Maybe we will one day even be able to print our own self-assembling structures and soft robots.

extremetech.com

by  | May 24, 2015 at 9:30 am

Advertisements

3D printed future – did you think about it ?

https://hbr.org/2015/05/the-time-to-think-about-the-3d-printed-future-is-now

MAY15_06_28731679_horz_b

The Time to Think About the 3D Printed Future Is Now

3-D printing, or additive manufacturing, is likely to revolutionize business in the next several years. Often dismissed in the popular mindset as a tool for home-based “makers” of toys and trinkets, the technology is gaining momentum in large-scale industry. Already it has moved well beyond prototyping and, as I explain in a new HBR article, it will increasingly be used to produce high-volume parts and products in several industries.

Since I prepared that article, new developments have only strengthened the case for a 3-D future – and heightened the urgency for management teams to adjust their strategies. Impressive next-generation technologies are overcoming the last generation’s drawbacks while adding new capabilities. This progress will speed up adoption and propel more experimentation and practical application. What was a niche technique is morphing into a broad-based movement driven by multiple technologies and many kinds of companies.

Many of the new developments have to do with broadening the science underpinning additive manufacturing. Early generations drew from physics and engineering. The new technologies are expanding the playbook into chemistry.Continuous light interface production, or CLIP, uses chemical reactions to better control the transformation of liquids into solids. Instead of slowly putting down a layer of material and then curing it, CLIP creates a monolithic product in what is essentially a continuous process. CLIP greatly speeds up production and boosts the material strength of the final product by cutting down on the problems created by layers. The inventors, who publicly announced this new approach in March, say they were inspired by the film “Terminator 2”  – specifically the scene where a robot reshapes itself after having melted into a puddle.

Another promising development is multi-jet fusion. This technology starts with a plastic or metal powder, but instead of solidifying the powder with a laser, it uses chemicals sprayed from 30,000 tiny nozzles at a rate of 350 million dots per second. These chemicals speed the shaping and hardening of the powder by a UV lamp. But importantly, in the future, the chemicals can also change the powdered material’s properties – adding color, elasticity, bacteria-resistance, hardness, and texture to the final product. And because the high-tech nozzles spray so quickly and precisely, the curing takes only a tenth of the time of existing 3D processes. Typical of next generation advances, it integrates a number of techniques that had been used separately.

Even more intriguing, though probably still years away, is what MIT calls 4-D printing, where the fourth dimension is time. These are objects embedded with “memory materials” that react to light or heat to form new shapes after delivery to the consumer. Imagine a piece of furniture that arrives flat, but then reshapes itself into a chair when exposed to sunlight.

And these are just the general-purpose technologies. Also emerging isxerographic micro-assembly, which promises to greatly improve computer chip manufacture by implanting components of chips with electrical charges and putting them in a highly conductive fluid. Electrical fields can then assemble these “chiplets” into full chips with greater capabilities and fewer defects than conventional chip production. Likewise in bio-printing, researchers are adding magnetic nanoparticles to living cells and then using magnetic fields to assemble the cells into artificial tumors and functioning tissues.

Big players are involved now in pushing additive manufacturing to the next level. Early phases of 3D printing involved startup companies with investments in the low seven digits. Stratasys and 3D Systems grew into industry leaders with approximately $1 billion in revenues each. Now we’re seeing much bigger stakes. Hewlett-Packard developed multi-jet fusion, leveraging its expertise in printer head technology to leapfrog the industry. CLIP comes from a startup,Carbon3D, but one with $40 million in funding from a VC group led by mainstay Sequoia Capital. MIT is investing heavily in 4-D printing. Xerox, which invented xerographic micro-assembly, had been testing the waters with an investment in startup 3D Systems. Once it saw the potential, it launched a major internal program leveraging many facets of its electronics expertise as well.

These organizations are putting their reputations as well as major capital investments on the line, and have a lot to lose if these technologies turn out to be vaporware. Carbon3D promises to release its first commercial printer by December of this year, while HP has a target date of January 2016.

The market is taking these claims seriously, as well. Both 3D Systems and Stratasys have seen their stock prices slide in recent months, in part because the market is worried about the next generation of technologies and the resources that giants like HP are putting behind them. Realizing they can’t spend like the giants, the early leaders have started shifting their R&D away from hardware and moving toward software, services, and consulting. The 3D printing ecosystem is still very much in flux.

In the midst of all this change, new strategies are required. Even if some of these new technologies fail to pan out, there’s so much activity going on, so much money and creativity now being applied, that we can safely expect the pace of additive manufacturing to pick up. That has two major implications for strategists. One is that timelines based on earlier generations of additive manufacturing may be too conservative. If the new technologies dramatically boost the speed and strength of 3D printing, then adoption rates will jump. The cost advantage of conventional “subtractive” manufacturing will disappear sooner than expected. The new capabilities to customize products will also be highly attractive. Digital platforms that coordinate 3D printing ecosystems will emerge sooner. Instead of moving incrementally to adopt 3D techniques into their organization, companies may need to pick up the pace.

Second, strategists will have to consider not only which technology to run with, but also whether to collaborate with these next generation pioneers. By partnering with, say, HP or Carbon3D, companies stand to gain earlier access. But they may also increase the risk if their chosen technology fails to meet its promise on schedule. Working with current 3D technologies, such as extrusion-, stereolithographic- and sintering-based methods has better odds but a smaller payoff. Such decisions could lead to internal strife between converts to each camp.  Companies could invest in both, but then they face the challenge of timing the switch over to the next generation, and the complexity of transitioning people and the organization from one to another, as well as the specter of writing off investments before they have been recaptured.

All of this is on top of the new level of complexity that 3D printing has brought to manufacturing generally.  What’s the proper mix of traditional “subtractive” methods with the new additive approaches. How much risk should a firm take on now, versus what’s the risk if you wait? And all of this raises the possibility of reshoring some operations, affecting established relationships with host governments and local unions.

Strategists, fasten your seat belts for a fun but bumpy ride.  Here’s where you show what you’re made of.

hbr.org

by Richard D’Aveni | MAY 06, 2015

 

4D printing vs 3D printing

http://www.smh.com.au/technology/sci-tech/4d-printing-is-cooler-than-3d-printing-and-why-that-means-the-end-of-ikea-flatpacks-20150420-1mp2aj

Professor Marc in het Panhuis holds a 4D printed valve that can change shape.

4D printing is cooler than 3D printing, and why that means the end of IKEA flatpacks

Just as you got used to the idea that toys, homewares, even guns can be built with 3D printers, the next phase is upon us. Researchers, including Australians, are already building objects with 4D printing, where time becomes the fourth dimension.

“4D printing is in essence 3D printed structures that can change their shape over time,” said inventor and engineer Marc in het Panhuis​. “They’re like transformers,” he says.

And their applications will be limitless. Imagine medical devices that can transform their shape inside the body, water pipes that expand or contract depending on water demand and self-assembling furniture.

Professor in het Panhuis’ team at the ARC Centre of Excellence for Electromaterials Science, located at the University of Wollongong, have just built an autonomous valve that opens in warm water and closes in cold water.

The valve is made out of four types of hard or soft hydrogels – networks of polymers – fabricated at the same time using a 3D printer.

Inside the valve’s structure a series of actuators respond to hot or cold water to open and close the valve.

While the valve’s shape change is activated by water, other 4D printed devices transform by shaking, magnets or changes in temperature.

“It’s a widely expanding field,” Professor in het Panhuis said.

“You can buy jewellery that’s 3D printed and changes shape when you put it on,” he said.

US inventor Skylar Tibbits, who runs MIT’s Self-Assembly Lab and coined the term 4D printing, is exploring 4D printing to manufacture furniture that can build itself.

“Rather than receiving a flat-pack and getting your screwdriver out, what he’s postulating is what if you just add a bit of water to it and it assembles itself,” Professor in het Panhuis said.

While its early days, the group are more advanced in their designs of pipes that can change their capacity, expanding and contracting when water demands increase or drop off.

The military is another industry interested in objects that can change shape or self destruct,Mission Impossible style.

“When armies are on the battlefield they leave a lot of electronics behind. What if you could make 3D printed electronics that [once the soldiers leave] undergo transient behaviour once they become too hot, or too cold, or too wet so they completely disappear so the enemy can’t use any of your materials,” Professor in het Panhuis said.

In 2012 DARPA researchers created implantable medical device that could deliver anti-microbial treatment to a wound site but would dissolve when no longer needed.

The electronic devices were made of ultra-thin silicon, magnesium and silk that could dissolve in the body, reducing the risk of a secondary site infection.

smh.com.au

by , Science Editor | April 22, 2015

4D printing ?

4D Printing Will Allow us to Morph a 3D Printed Object Into Any Shape!

http://goo.gl/n6XMnX

A grid was made by 4D printing.

Using a new technique known as 4D printing, researchers can print out dynamic 3D structures capable of changing their shapes over time.

Such 4D-printed items could one day be used in everything from medical implants to home appliances, scientists added.

Today’s 3D printing creates items from a wide variety of materials — plastic, ceramic, glass, metal, and even more unusual ingredients such as chocolate and living cells. The machines work by setting down layers of material just like ordinary printers lay down ink, except 3D printers can also deposit flat layers on top of each other to build 3D objects.

“Today, this technology can be found not just in industry, but [also] in households for less than $1,000,” said lead study author Dan Raviv, a mathematician at MIT. “Knowing you can print almost anything, not just 2D paper, opens a window to unlimited opportunities, where toys, household appliances and tools can be ordered online and manufactured in our living rooms.”

Now, in a further step, Raviv and his colleagues are developing 4D printing, which involves 3D printing items that are designed to change shape after they are printed. [The 10 Weirdest Things Created By 3D Printing]

“The most exciting part is the numerous applications that can emerge from this work,” Raviv told Live Science. “This is not just a cool project or an interesting solution, but something that can change the lives of many.”

In a report published online today (Dec. 18) in the journal Scientific Reports, the researchers explain how they printed 3D structures using two materials with different properties. One material was a stiff plastic, and stayed rigid, while the other was water absorbent, and could double in volume when submerged in water. The precise formula of this water-absorbent material, developed by 3D-printing company Stratasys in Eden Prairie, Minnesota, remains a secret.

The researchers printed up a square grid, measuring about 15 inches (38 centimeters) on each side. When they placed the grid in water, they found that the water-absorbent material could act like joints that stretch and fold, producing a broad range of shapes with complex geometries. For example, the researchers created a 3D-printed shape that resembled the initials “MIT” that could transform into another shape resembling the initials “SAL.”

“In the future, we imagine a wide range of applications,” Raviv said. These could include appliances that can adapt to heat and improve functionality or comfort, childcare products that can react to humidity or temperature, and clothing and footwear that will perform better by sensing the environment, he said.

In addition, 4D-printed objects could lead to novel medical implants. “Today, researchers are printing biocompatible parts to be implanted in our body,” Raviv said. “We can now generate structures that will change shape and functionality without external intervention.”

One key health-care application might be cardiac stents, tubes placed inside the heart to aid healing. “We want to print parts that can survive a lifetime inside the body if necessary,” Raviv said.

The researchers now want to create both larger and smaller 4D-printed objects. “Currently, we’ve made items a few centimeters in size,” Raviv said. “For things that go inside the body, we want to go 10 to 100 times smaller. For home appliances, we want to go 10 times larger.”

Raviv cautioned that a great deal of research is needed to improve the materials used in 4D printing. For instance, although the 4D-printed objects the researchers developed can withstand a few cycles of wetting and drying, after several dozen cycles of folding and unfolding, the materials lose their ability to change shape. The scientists said they would also like to develop materials that respond to factors other than water, such as heat and light.

LIVESCIENCE.COM
by Charles Q. Choi, Live Science Contributor   |   December 18, 2014 12:22pm ET