RoBio Systems develops devices using Microfluidics and, thanks to its investment in EdgeCAM, the company is delivering the rapid design iterations and fast turnaround times that its customers require.
RoBio Systems was formed in 2004 as a microtechnology company to provide engineering consultancy, product design, prototyping and manufacturing for the biology and biotechnology industries. The RoBio Systems team already had a proven track record in microfluidics since the founders of the company - chemists, biologists and engineers - all carried out pioneering work in the field as members of the Bio and Chemical Instrumentation group at CRL, formerly the Thorn EMI Corporate Research Laboratories.
Flexibility is of the essence
Bryan Miller, Fabrication Technologies Engineer at RoBio Systems, says: "We are primarily concerned with developing microfluidics devices that handle biological samples, developing them into products not available elsewhere in the market. Many of our designs are based on moulded PDMS (silicone rubber) bonded to glass. We create master moulds with multiple machined microscopic cavities into which we inject silicone to make the actual devices. The mouldings generally comprise a network of channels tens of microns deep, connecting multiple ports and wells formed by upstands. These often have complex geometries and have precise dimensions to give accurate mould closure. The mouldings are then plasma-bonded to glass such as a microscope slide. A non-contaminating joining technique like this is vital in biological applications.
"For our major client, flexibility is of the essence. That is why we do everything in-house: concept design and testing, prototyping and manufacturing. Our strength is the ease with which we iterate designs, being able to make, test and review a new design idea on as short as a two-day cycle. This leads to faster and lower-risk design development."
Knowing exactly what to look for
Bryan Miller again: "I guess you could call us educated users. Because of our previous experience we knew exactly what to look for when setting up RoBio Systems and we budgeted for this from the outset. The complex central zone of our devices contains all our ingenuity and the only effective way to design it is in 3D. For that we chose SolidWorks.
"We then looked for a CNC solution that was intuitive and easy-to-use and would be up and running quickly on company start-up. In order to meet our turn-round times, the CNC software would also have to work seamlessly with SolidWorks models without translation or intervention. It would have to drive our Kern high-precision micro milling machine, too."
Demonstrating the importance of 2D/3D integration
According to Bryan: "We researched the possibilities through the internet and various message boards and forums. Rejecting expensive software that was rated as complicated to use, eliminating low-cost software with limited functionality and poor support, we reduced our list of ten potential suppliers to just two: EdgeCAM and one other. We downloaded and tried time-limited evaluation versions of both and invited the suppliers to demonstrate to us.
"At the formal EdgeCAM demonstration, we saw the integration of 2D and 3D; this is important to me, because much of what I need to do to complete the mould, adding alignment pins, silicone inlet ports and so on, is best done in 2D.
"Simulation was vital, too. Because of the extremely fine machining involved, we needed to be absolutely certain that the programmes would run correctly. Previous CAM software I had used let me down in this respect and I did not want a recurrence.
Free-standing EdgeCAM works seamlessly with SolidWorks
There were other factors to consider, as Bryan points out: "Working on very fast turn-round, we needed separate seats of design software and machining software so that the designer and the manufacturing engineer could work on the same part simultaneously. EdgeCAM was completely freestanding but the alternative we looked at required its own dedicated copy of SolidWorks to get the same functionality. Had we gone that way, it would have added significantly to the cost of the solution.
"Another important point: EdgeCAM, a SolidWorks Certified CAM product, was more Microsoft Windows-compliant and easier to use than the alternative we looked at."
EdgeCAM Code Wizard saves the day
The decision was made to use EdgeCAM Solid Machinist. Bryan explains: "It all came down to the quality of the EdgeCAM solution. The difference in cost between the different packages did not make a huge difference. EdgeCAM has proven to be very easy to use. I can use simple pre-set blocks operations or I can define for myself every element of the toolpath.
"The software was installed over a year ago. I familiarised myself with it, then took the training, which, by the way, was spot-on. Since then we have produced up to 20 programs and changes a day.
"We had chosen a KERN Micro high-precision five-axis micro-milling machine because of its better than +/-1micron precision, though, in the interim, we hired a Datron mill. That meant I had to face the problem of buying two post processors, but EdgeCAM's no-cost Code Wizard post-processor generator saved the day. I had expected that the process would be complicated, but it was not - far from it. No other CNC software we looked at had anything like it."
EdgeCAM/SolidWorks associativity reduces time to manufacture
RoBio Systems produces hundreds of designs a year, with many and frequent design iterations. "With this solution," says Bryan, "Malcolm Austen, our Head of Design, can be using SolidWorks to design the 'business end' of our designs whilst I can be working on the same part using EdgeCAM. Thanks to the association between the two, I am immediately alerted to changes that Malcolm has made to the model and offered the option to regenerate the toolpath or not. Doubling up in this way significantly reduces our time to manufacture."
By using EdgeCAM, Bryan has also been able to eliminate the tool gouges that plagued him at CRL. He says: "There, we would find we could machine the part correctly, but because of the extremely small size of the features, we would get to the end of the machining cycle only to find the features may have been machined over on tool entry or exit. When this happened, we would have to use all our ingenuity to adjust the programme. We would also get frequent programme crashes if we were making a single mould with repeated and identical cavities. It was a time problem rather than a material cost problem. We could lose valuable hours getting programs right. Now, we have no such problem. Not only does EdgeCAM work properly in this respect, we can properly simulate the toolpath, manipulating the part and zooming in so that we can get a really good view of what was going on.
"The time we have saved through eliminating tool gouges has enabled us to do much more machining than we used to. The effect of errors; I do not actually get any."
EdgeCAM is a massive leap forward
Summing up, Bryan says: "We had never actually heard of Pathtrace until we started looking. We found they were very professional and knew their stuff. Thanks to the combination of SolidWorks, EdgeCAM and Kern we are now able to make anything we design. EdgeCAM alone has driven out many hours from the process compared with the previous software I had used. Another important factor is the ease with which we will be able to upgrade to simultaneous four- and five-axis, something we will need to do as our designs evolve.
"Pushing the accuracy envelope, we have complete confidence that a 20-micron deep channel in an SW model will also be a 20-micron channel in the finished part. Our customers are very impressed with what we have delivered, a testimony to our whole approach. EdgeCAM is a massive leap forward. I cannot fault it in any way."
