Digital Hydraulic Drive for microfluid large-scale integration system based on shape memory alloy actuators

In many areas of the life sciences it is becoming increasingly important to analyze living cells individually in order to explore the significance of cell heterogeneity, the phenotypic differences between genetically identical cells and the influence of variations in the cell cycle for cell biological studies. Therefore, different methods have been published to show tools to separate, sort and manipulate single cells which could accelerate research in the life sciences towards single cell resolution. Microfluidic large scale integration (mLSI) is one of the well-known plattforms for single-cell research that has been developed since 2002 [1] and optimized by many researchers in recent years [2]. However, the main issue with mLSI is that the external pressure sources are rather bulky and inconvenient to operate due to their huge size and complex structure, which hampers the uptake of this technology in Point-of-care (POC) applications Here, we present a small size and low power Digital Hydraulic Drive (DHD) intended for use in miniaturized and portable control systems for mLSI chips. The main components of a DHD are a pneumatic cylinder and a shape memory alloy (SMA) actuator [3]. Depending on different types of SMA actuators, the DHD is not only able to provide digital hydraulic pulses (switching time smaller than 1 s), but can maintain a steady state up to 24 hours. A single DHD enables to control 256 mLSI valves in parallel.