Lab on a Chip, Microfluidics, and Sample to Answer are terms we hear a lot when designing medical devices. For years the trend has been to integrate more and more laboratory functions into small disposable chips or cartridges with the ideal goal of being able to perform all the functions from sample preparation to detection in a single disposable on one instrument. This has led the instruments disposable interfaces to be increasingly complex. Sometimes there are hundreds of electrical connections for internal sensors or actuators, multiple heaters for PCR amplification, systems for magnetic bead capture, pressure connections for fluid control, actuators for dispensing stored fluids, and external sensors just to name a few. The complex interfaces required can cause many design challenges, but after working on several of these types of projects over the years we’ve learned there are some ways you can make your life easier, and end up with a better design.