October 8, 2013
A little over a year ago, Rich Ranky was at Northeastern, working on research for his PhD about how to build a force-measuring sensor into a plastic component. Back then, Ranky was injecting conductive slurry into plastic pieces with a caulking gun. Now, his 3D printer, Donatello, prints patented sensors that measure temperature, vibration, heart sensors and electricity, all for a cost between $10 to $15.
Ranky spun his company, 3-Spark, out of Northeastern with professors Constantinos Mavroidis and Mark Sivak. He received $100,000 in seed funding from the University, and uses the school’s machine shops for most of his hardware development.
“I feel like Northeastern’s baby,” Ranky said, laughing. “They have been really, really good to me.”
Though he appreciates the exercise he gets from biking back and forth from Northeastern to MassChallenge, Ranky is lobbying the accelerator to install a machine shop somewhere in the building, perhaps in the new location at the Innovation Design Center. Until that time, things will continue to be a little chaotic for 3Spark, but not nearly as chaotic as the printer itself.
As Ranky explains the inner-workings of the printer:
There is a plastic deposition system which is the plastic laying down the housing and framework of the structure, and then there is the conductive deposition system—patent-pending—which is putting the conductive material down. However, you design it in the computer, the plastic goes through the layers and it will leave a channel half open and then with the motorized syringe, it offsets and squeezes the conductive material into the channel and the plastic continues building on top of it.
Basically, the plastic body of the sensor is printed layer-by-layer, sort of like a reverse shredder. As it builds it leaves a little gap, which is filled with conductive material resulting in what looks like a metal splinter.
Ranky admitted he only understood some of the chemistry and some of the material science, which is why he is bringing a material scientist consultant on to his team. But, as he was explaining how his material components work, he clearly demonstrated that he is an expert in his field, bar none.
We are working with the family of conductive elastic suspensions. The one we are using is an off-the-shelf graphite filled silicon. There are other companies doing research with things like silver or platinum particles, or copper or solder. A lot of those solutions are good, but they tend to be brittle and I liked the elastic conductive suspensions, because you can strain them and flex them and distort them a little bit. And you can measure that change electrically and they will still return to its original shape.
Ranky sees the technology as having the most potential in bio-medical manufacturing and R&D, as well as academia, where all the research for applications of the technology will be done. But he also foresees applications in industrial design and architecture.
“I love the creative freedom that this technology gives people from all ranges of technological backgrounds,” he said.
As an example, Ranky showed me a version of a handle—for which he has a patent—he built for a stationary exercise bike, that could monitor biometrics on stroke patients.
He is hard at work on version two of the printer, and will hopefully be ready to publicly demo the technology in 2014.
The next printer will be called either Michelangelo or Leonardo. Yet, I think Donatello—the brains of the Teenage Mutant quartet—is the most appropriate for this futuristic tech.