Fabrisonic embeds sensors in NASA’s rocket fuel piping using 3D printing

Ohio-based solid-state metal 3D printing specialist Fabrisonic, and optical sensor specialist Luna Innovations, have collaborated a3 D printed sensor project for NASA. The team was contracted to help gather data in cryogenic fuel pipes for rocket test stands at NASA Stennis Space Center. Leveraging the capabilities of its patented Ultrasonic Additive Manufacturing technology (UAM) technology, Fabrisonic was […]

Interview with Fabrisonic on Embedding Sensors in 3D Printed Metal Parts

Fabrisonic has a very unique 3D printing technology. The company’s UAM (Ultrasonic Additive Manufacturing) process can take layers of metal tapes and through ultrasonically welding them and then machining them create 3D objects. Ultrasonic vibration has been used as a welding technology before but the firm has commercialized it for our market now. UAM lets you do very exciting things such as joining different metals, work with relatively inexpensive feedstock and embed sensors in metal parts. Now Fabrisonic is lowering the cost to get started with their technology by offering an entry-level machine, the SonicLayer 1200 for $200,000. Often times Fabrisonic can seem kind of a Don Quichote of 3D printing pioneering an own path that is very different than other companies all working on the same technologies. Can the firm go it alone? Or will it succumb to a VHS wars kind of pressure where Video 2000 lost to the wider adopted VHS? Will it find a niche such as the one it is trying to carve out in embedded sensors? Or will it find broader use but for heat exchangers or exotic blends of metals? We sat down with Fabrisonic’s brilliant Mark Norfolk to find out.

The New Fabrisonic 1200

How is Fabrisonic doing? 

Were continuing on our growth curve. We’re a very small firm at the moment consisting of 8 people. In the next year we’ll be adding five people. We want to be a growing, strong & viable business. We’re all engineers so we want to build solid businesses. 

We are a spin out of a nonprofit, EWI. So far we’ve been bootstrapping the business. Its a question of slow and steady with a focus on the long term.

At the moment we’re evenly split between service and machine sales. In house we operate five of our own machines. We’ve just launched our Fabrisonic 1200 which is a very capable machine that lowers the price point at which people can use our technology.

We’re very curious about emerging applications in electronics, sensors, IoT. One key aspect of our technology is that we can integrate electronics into metal structures. We see expanding interest into that application in process monitoring, industry, aerospace and other industries.

What are some examples of things that people are making with Fabrisonic? 

One example is an embedded fibers optic sensor inside a metal part. What we can get from this is the actual load data from the component. In the demonstration case, it is a part of a wing. What our customers can do with this is to monitor the strain on the wings for example. This kind of application can be very useful in commercial aerospace. You could also track strain on the landing gear on every landing to predict failure or maintenance. 

What is also being done is embedded thermocouples so we can get precise temperature measurements in specific places in a reaction vessel. Some of our customers want to very precisely measure temperatures in chemical reactions and use Fabbrisonic to put sensors exactly where they need to be. By placing the thermocouples inside the reaction vessel they can get the right data to adjust and control the reaction.

Another example of a  sensor is inside a base plate used for PBF for metals. The embedded fiber optic cable in the base plate can monitor the process while the PBF machine is running. We can determine the strain, magnitude, and vector during the print job, Besides metal 3D printing such careful monitoring would be advantageous in many machines and processes. 

Another application that we’re seeing is piezo microphones being used to detect cracks in metal structures to monitor failure or fatigue. We’re making sensors to measure magnetic fields and also making waveguides.

We’re helping to tackle challenges in health monitoring and also of things like wings, structures or a pole. 

 

Embedded fiber optic strain sensors.

What are some of the advantages of your technology? 

One of the biggest benefits is that we’re a solid state process. We’re not melting the part or changing the metallurgy of the part.  Material cost is also low at $5 to $10 a pound. Besides embedding electronics in metal, we can use dissimilar metal and join them together. We can make gradient materials as well. A lof what you can do with our technology is emerging. We’re doing things whereby a part can become a barcode, that is serialized through the different thicknesses of the part itself. This ensures that the part itself can vouch for its own tracing and security.

A copper and aluminum part.

Why is 3D printing heat exchangers so promising?

It lets you get the coolant exactly where you want it. Without a lot of different production steps. You can pull out mass, increase performance and do part consolidation all at the same time. 

With electric cars will there be possible demand in that arena for your technology?

For sure. We are seeing a lot of things where 3D printing could reduce part count and improve performance in electric vehicles and batteries. Structures could be heat sinks as well for example. Cool things.

What work has been done on microchannel heat sinks in heat exchangers?

We’ve made 10,000th of an inch channels in heat exchangers. This lets you get more surface area, in order to get more heat out faster. You can then integrate that anywhere in your structure. Or by varying dissimilar metals get different temperature gradients. The thinking has changed, your thermal unit is also structure.

Can you make gradient/functionally gradient parts with Fabrisonic?

The big thing for gradient, for us now, is to use it where is a transition; in temperatures for example. When monitoring or controlling for CTE (Coefficient of Thermal Expansion) we can use the layering of different materials to avoid sharp temperature differences. Fatigue cracks can also be avoided through this method.

Research Group Creates 3D Printed Sensor that Changes Color When Exposed to Wet Conditions

In the dry state (left; in an anhydrous liquid), the sensor material is purple; in the wet state (e.g. from air humidity) it turns blue. These 3D printed workpieces are each about one centimeter wide. [Image: Verónica García Vegas, UAM]

A collaborative group of scientists from the Autonomous University of Madrid (UAM), the Hebrew University of Jerusalem, the Nanyang Technological University in Singapore, the Institute for Materials Science in Madrid (ICMM-CSIC), and the Deutsches Elektronen-Synchrotron (DESY) worked together to develop a versatile 3D printable sensor, made of an inexpensive plastic-composite, that can detect tiny amounts of water and change color in wet conditions.

The team, led by UAM’s Pilar Amo-Ochoa, developed the flexible, non-toxic material, which will change from purple to blue when exposed to moisture, and detailed their work in a research paper, titled “3D Printing of a Thermo- and Solvatochromic Composite Material Based on a Cu(II)–Thymine Coordination Polymer with Moisture Sensing Capabilities,” that was recently published in the journal Advanced Functional Materials.

The abstract reads, “This work presents the fabrication of 3D‐printed composite objects based on copper(II) 1D coordination polymer (CP1) decorated with thymine along its chains with potential utility as an environmental humidity sensor and as a water sensor in organic solvents. This new composite object has a remarkable sensitivity, ranging from 0.3% to 4% of water in organic solvents. The sensing capacity is related to the structural transformation due to the loss of water molecules that CP1 undergoes with temperature or by solvent molecules’ competition, which induces significant change in color simultaneously. The CP1 and 3D printed materials are stable in air over 1 year and also at biological pHs (5–7), therefore suggesting potential applications as robust colorimetric sensors. These results open the door to generate a family of new 3D printed materials based on the integration of multifunctional coordination polymers with organic polymers.”

3D printed sensors have many potential uses, such as cardiac research, an early warning system for wildfires, and other water-related applications, like determining how much water a plant is using. But the demand is increasing across many industries for responsive sensors that can quickly change, in a simple way, when they are exposed to specific molecules…such as water, which is one of the most common chemicals monitored by these types of sensors.

“Understanding how much water is present in a certain environment or material is important. For example, if there is too much water in oils they may not lubricate machines well, whilst with too much water in fuel, it may not burn properly,” explained scientist Michael Wharmby, a co-author of the paper and head of DESY’s beamline P02.1.

DESY, a national research center in Germany, operates particle accelerators, and the team examined their new sensor material with the X-ray light source PETRA III at Wharmby’s beamline. Using X-rays to investigate the material allowed the team to better understand the internal structural changes that water triggers, which lead to the color change.

Additionally, these high energy X-rays revealed that the functional part of the material – the versatile copper-based coordination polymer – was in fact working.

José Ignacio Martínez, a co-author of the paper from ICMM-CSIC, said, “Having understood this, we were able to model the physics of this change.”

This compound, known as CP1, consists of a water molecule that’s bound to a central copper atom. Once the sample is heated i[ to a certain temperature, the water molecule is removed, which then leads to the material going through a reversible structural reorganization that ultimately causes the color to change.

“On heating the compound to 60 degrees Celsius, it changes colour from blue to purple. This change can be reversed by leaving it in air, putting it in water, or putting it in a solvent with trace amounts of water in it,” explained Amo-Ochoa.

Front and side views of the computed optimal geometries for the compound CP1

Then the team mixed the copper compound into a 3D printing ink, which they used to 3D print sensors in a variety of different shapes. The sensors were tested in the air, and also with solvents that contained different amounts of water, which revealed that the porous objects were even more sensitive than the compound itself to the presence of water.

The 3D printed sensors were able to detect 0.3 to 4% of water in solvents in less than two minutes, while they could detect a relative humidity of 7% in air. If the material is dried, either through heating or in a water-free solvent, it will return to purple. The team’s research showed that the material will remain stable over many heating cycles, and that it remains stable in the air for at least one year, at biologically relevant pH ranges of 5 to 7. Additionally, the copper compounds are shown to be evenly distributed throughout each sensors.

Co-author Shlomo Magdassi from The Hebrew University of Jerusalem said that the team’s concept could eventually be used to create additional functional materials in the future, for use in a wide range of industries.

“This work shows the first 3D printed composite objects created from a non-porous coordination polymer. It opens the door to the use of this large family of compounds that are easy to synthesize and exhibit interesting magnetic, conductive and optical properties, in the field of functional 3D printing,” said co-author Félix Zamora from UAM.

Co-authors of the paper are Noelia Maldonado, Verónica G. Vegas, Oded Halevi, Martínez, Pooi See Lee, Magdassi, Wharmby, Ana E. Platero-Prats, Consuelo Moreno, Zamora, and Amo-Ochoa.

Discuss this research and other 3D printing topics at 3DPrintBoard.com or share your thoughts in the Facebook comments below.

[Source: EurekAlert]

Fabrisonic’s Whitepaper on Metal 3D Printed Heat Exchangers for NASA JPL

Founded in 2011, Ohio-based Fabrisonic uses its hybrid metal 3D printing process, called Ultrasonic Additive Manufacturing (UAM), to merge layers of metal foil together in a solid-state thanks to high frequency ultrasonic vibrations. Fabrisonic mounts its patented hybrid 3D printing process on traditional CNC equipment – first, an object is built up with 3D printing, and then smoothed down with CNC machining by milling to the required size and surface. No melting is required, as Fabrisonic’s 6′ x 6′ x 3′ UAM 3D printer can “scrub” metal foil and build it up into the final net shape, and then machines down whatever else is needed at the end of the process.

Last year, Fabrisonic’s president and CEO Mark Norfolk told 3DPrint.com at RAPID 2017 that about 30% of the company’s business was in heat exchangers, as the manufacturing process is a lot smoother thanks to its low-temperature metal 3D printing technology – no higher than 250°F. UAM makes it possible to join metal alloys that are notoriously difficult to weld, such as 1000, 2000, 6000, and 7000 series copper, aluminum, stainless steel, and exotic refractory metals…all of which are used in the heat management systems at NASA’s Jet Propulsion Laboratory (JPL).

[Image: Sarah Saunders]

Justin Wenning, a production engineer at Fabrisonic I spoke with at RAPID 2018 this spring, recently published a whitepaper, titled “Space-grade 3D Metal Printed Heat Exchangers,” that takes a deep dive into the work he’s been doing with Fabrisonic’s 3D printed metal heat exchangers for aerospace applications. The company participated in a two-year program at JPL, and 3D printed a new class of metal heat exchanger that passed JPL’s intense testing.

“For every interplanetary mission that JPL oversees, numerous critical heat exchanger devices are required to regulate the sensitive, on-board electronic systems from temperature extremes experienced in space. These devices can be small (3 in. x 3 in.) or large (3 ft. x 3 ft.),” Wenning wrote in his whitepaper.

For many years, NASA glued bent metal tubes along, and fastened them to, the exterior of a space vehicle’s structure, which weigh a lot and do not perform well thermally. These devices were also assembled and quality-checked by hand, so production could take up to nine months. At the end of its partnership with NASA JPL, Fabrisonic showed that 3D printing can be used to improve upon all of these issues.

Evolution of UAM 3D printed heat exchanger with NASA JPL. Samples began small to
evaluate benchmark burst and helium leak performance in 2014. The team then began focusing on technology scale-up and system integration. The culmination is a full-size, functioning heat exchanger.

The UAM system does not use any controlled atmospheres, so the part size and design range greatly. NASA JPL first started working with Fabrisonic in 2014, thanks to a JPL Spontaneous R&TD grant, to look into small, simple UAM heat exchangers, before moving up to larger structures in 2015 through NASA’s SBIR/STTR program. The result was a full-size, functioning heat exchanger prototype for the Mars 2020 rover mission that was fabricated in far less time, with a 30% lighter mass.

The 3D printed heat exchangers that Fabrisonic creates involve building pumped-fluid loop tubing right into the structure for additional efficiency and robustness, as the company’s UAM process can also be used to mix and match materials, like copper and aluminum.

UAM starts with a metal substrate, and material is then added to and removed from the structure to make the device’s internal passageways. To help with material deposition, a proprietary water-soluble support structure is added, before adding strength and features, respectively, with optional heat-treating and final CNC machining. Fabrisonic then added SS tubing, which helps with fitting attachments, to the aluminum structure with friction welding for NASA JPL’s development parts.

NASA JPL also needed to raise its technology readiness level (TRL) from 3 to near 6. During the program, Fabrisonic and its EWI affiliate 3D printed and tested dozens of different heat exchangers, in order to develop a final prototype for ground-based qualification standards based off of NASA JPL’s existing heat exchangers.

UAM process steps for fabricating NASA JPL heat exchangers.

The NASA JPL TRL 6 qualification included several tests, including proof pressure testing to 330 PSI, two-day controlled thermal cycling from -184°F to 248°F in an environmental chamber, and vibration testing on an electrodynamic shaker, which simulated a common day rocket launch (1-10 G) in all orientations while attached to a dummy mass at the same time for imitating a normal hosted electronics package. Other tests included:

  • Burst testing greater that 2500 PSI with a 0.030-in. wall thickness
  • Helium leak testing to less than 1×10-8 cc/s GHe between thermal and vibration testing
  • Full 3D CT scans of each specimen before and after mechanical testing, in order to evaluate void density and any accumulated testing damage

JPL project with copper embedded. [Image: Sarah Saunders]

Each of the three UAM 3D printed heat exchanger components passed the qualifications, which raised the technology to its goal of near TRL 6. To corroborate the results, NASA JPL scientists completed more helium leak and burst testing, along with thermal shock testing on certain devices; this involved submerging certain heat exchangers in liquid nitrogen (-320°F) to test their bi-metallic friction welded stainless steel aluminum joints. According to the whitepaper, the joints were “robust and helium leak tight” post-submersion.

Fabrisonic’s new class of 3D printed metal heat exchanger, developed under NASA JPL, has uses in other commercial production applications, which the company is currently exploring.

“For instance, the lack of melting in UAM enables the integration of multiple metals into one build since high temperature chemistry is avoided,” Wenning wrote. “Thus, copper may be integrated as a heat spreader in critical locations improving thermal performance with a small weight penalty.”

Because of its low temperatures, UAM can also be used to embed sensors into solid metal. In 3D printed heat exchangers, sensors could help monitor system health and improve control by being integrated in important locations.

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[Images: Fabrisonic unless otherwise noted]