Posted July 25th, 2013 by Engineering

Building Open-Source Science with the DropBot

Ryan Fobel poses next to his DropBot prototype.

Ryan Fobel (IBBME PhD candidate) poses next to his DropBot prototype.

“When it doesn’t really exist anywhere you have to build your own,” said Ryan Fobel (IBBME PhD candidate), who is the mastermind behind the DropBot, a ‘digital microfluidics’ research tool that may just spark a revolution in biomedical engineering research. According to Associate Professor Aaron Wheeler, who holds the Canada Research Chair in Bioanalytical Chemistry at the Department of Chemistry, the Institute of Biomaterials & Biomedical Engineering (IBBME), and the Donnelly Centre for Cellular and Biomolecular Research (CCBR), microfluidics can be understood as a tiny “bit of plumbing that we can apply to lots of interesting things: diagnostics, chemical synthesis, tissue engineering, cell culture and analysis.” But it’s also a very new – and relatively untried – research field. “We’d been holding high-voltage probes with our hands, touching these to microchips we built ourselves. The results were not reproducible,” said Fobel. So he enlisted the help of his brother Christian, a recent PhD in Computer Science, to help him create a machine that the Wheeler lab has affectionately named “DropBot.” The machine digitally navigates droplets across a surface in much the same way one would navigate a game of Ms. Pacman. In fact, when viewed on the computer screen, the tiny microfluidic device bears an uncanny resemblance to a chessboard as drops are pushed from one square to the next by computer-controlled signals. According to Fobel, “Now we can be doing 10 things simultaneously, which allows you to scale up your productivity. We should get better results, too, as we’re removing a source of error from our experiments.” The machine works. There’s just one problem. “Digital microfluidics is still in an early stage,” said Professor Wheeler. “There are a few of us working very hard, demonstrating some interesting ideas. But for the technique to really explode and be widely used we need to get it in to the hands of more people. Until now we haven’t had a chance to see what it can really do,” he said. Rather than trying to sell his invention, Fobel, who built his machine largely on popular open-source technology such as the Arduino board, a major component in 3-D printing technology, decided to post the source code on the Internet as an open-source file. Anyone can download the blueprints, instructions and software for DropBot and build their own instrument. Users are encouraged to individualize their new Dropbots, and post their changes and results. For Fobel, it’s a move that makes sense. “This is a really good way to advance microfluidics research quickly,” he explained. “I’d love it if people would use it. I hope this is the way we can share this technology with people all over the world. Besides, if everybody out there was building their own system it would be like reinventing the wheel.” But, he added, there’s another reason for making the code public: “Nothing is ever finished with these things. You would always want to make the tools better and easier to use.” Already the move has been a popular one. Since publishing a paper on the DropBot in Applied Physics Letters last month, Fobel has been contacted by several researchers from as far away as Germany and California interested in building a DropBot prototype. According to Wheeler, Fobel is “unique” among his graduate students. “Ryan has transformed the capabilities of my lab,” he said. Fobel has been tapped to share his experiences with the DropBot at a conference on open-source hardware at MIT in the fall. In the meantime, Fobel has another DIY project on tap: he and his lab mates are building their own 3D printer, which will allow them to print parts for the next DropBot prototype.