Additive manufacturing: building blocks for the future
Even though we grew up on opposite sides of the world, my colleague Prabhjot Singh in India, and I in Ohio, both of us had the same favorite toy as young boys, building blocks. Starting with a few simple shapes, we could build structures limited only by our imagination. First it was a house, then it was a factory, then it was baseball stadium, or was that a soccer park? We could build almost any solid shape just by adding the blocks by hand, one at a time, to the structure (and mixing in a little bit of imagination.) After many years, and comments from our friends that we haven’t grown up, we find ourselves still imagining interesting structures and ”playing with blocks” to build things all over again.
Every science student learns that the real “building blocks” that make up every structure are atoms and molecules. By exploiting the electronic properties of the individual atoms and molecules, we can again build structures that are only limited by our imagination. However, moving atoms and molecules, by hand, one at a time, isn’t an option. This is why my colleague Prabhjot and I, who are not only from different parts of the world, but from different technical backgrounds as well, have found ourselves working together.
Prabhjot’s technical background focused on manufacturing technology. In many ways the concept of additive manufacturing is much like the reference I used earlier, stacking building blocks. It is the name given to a set of manufacturing methods wherein very complex geometries are built by assembling a set of simple layer cross-sections. Additive manufacturing machines are often called 3D printers. A key research challenge is enabling such 3D printers to print complex shapes in functional materials where properties besides the shape are important. While in graduate school, Prabhjot devised algorithms to stack material along multiple directions to make increasingly complex parts such as those used in aerospace structures. When he first joined GE Global Research, he worked with a team of engineers and materials scientists to construct a 3D printer to make ceramic parts for aerospace applications. Because this printer was based on a digital projector, they started to call the process digital micro-printing.
On my side, while in school, I studied materials and worked on connections between structure and function in exotic chemical compounds. When I began working at Global Research, real-time ultrasound imagers were new and exotic. Today, as you know if you’ve read my previous blog entry, GE has a big medical ultrasound business that makes a wide range of imagers from high-end machines for major teaching hospitals, all the way to portable and ultraportable machines that fit in your pocket.
All of these imagers contain a transducer, which is the part that actually touches your body. The transducers use a dense array of elements, each converting electrical signals into ultrasound waves, and vice versa. GE has been building them for years, but it is a hard process and hasn’t gotten much better throughout the years.
Prabhjot tells me that early in the development of digital micro-printing, he showed the technology to Tom Batzinger, one of the ultrasound experts and technology evangelists at Global Research. Tom immediately recognized its potential as a novel method for making ultrasound transducers. Pretty soon, word got around about digital micro-printing’s potential application in making ultrasound transducers, prompting my own interest.
During our annual technology expo, called Techfest, I stopped by a digital micro printing demo that Prabhjot was hosting. Almost as soon as we started talking, we realized that additive manufacturing using digital micro-printing offered a single platform to perform almost all of the manufacturing steps needed to build transducers: Piezoelectrics, matching layers, and the adhesive joints between them. Moreover, over the years ultrasound researchers have proposed many novel transducer designs that have been between hard and impossible to realize because the manufacturing process is so complex. As we continued to explore digital micro-printing, we realized that many of these designs become simpler with additive manufacturing technology.
For a couple of years now, we have worked together and with some of the center’s ceramicists, such as Tony Brewer and Venkat Venkataramani, to improve the technology. Two years ago the National Institute of Biomedical Imaging and Bioengineering awarded GE a contract to extend the method for point of care maternal health applications. Since then, we have built up the team, which includes Michelle Bezdecny, who you see in the video above demonstrating the technology.
Additive manufacturing for ultrasound is a wonderful example of working on the interface among different scientific disciplines and one of the truly unique things about Global Research. With some imagination, it is possible to envisage a future where it would be possible to form a wide range of transducer arrays on a single automated assembly line. It’s been an evolving case of a good idea being even better than we thought it was. I think I speak for Prabhjot and myself when I say that we really enjoy this dynamic intellectual environment where progress comes not only from individual effort, but from the interplay of multiple technologies where everybody can learn from each other. That’s one of the reasons it’s more fun to come work in the lab where we can do things nobody has ever done before.
Although at home, we have been known to play with Legos.