Wireless Control of Electrowetting Devices

This paper presents a general firmware for controlling microfluidic operations using wireless communication. The firmware is data driven, thus, offers a great deal of flexibility in design and testing of Electro-wetting on dielectrics (EWOD) chips. The control is executed with the help of structured commands that holds actuation information for each electrode. A serial communication link between the microcontroller and the host PC is established using XBee wireless modules to allow data transfer in both directions. A shortest path algorithm has been developed to direct droplets from a given source to a destination in minimum number of actuations, circumnavigating stored droplets that act as obstacles. The algorithm is very efficient in searching paths and is independent of the size of electrode array. The list of electrodes along the path is used to write a simple script. The script is the input to the embedded code which automatically generates the actuation signals.