(102e) Automated Capillary Force Layer-by-Layer (CF-LBL) Assembly of Polyelectrolytes

In the layer-by-layer (LBL) process, alternating charged or other complementary interacting species are deposited onto a substrate in sequences. LBL assembly enables the tunable design and fine control of functional materials into nanoscale thin films, which has found diverse applications in reactive membranes, drug delivery systems, and electrochemical and sensing devices.  However, as the field continues to expend to pursue new discoveries in cell biology and commercial translation in pharmaceutical industry, several engineering challenges need to be overcome, such as low viability of film architectures and morphologies, over-consumption of building materials, and non-sterile environment during film preparation.

Herein, we present a simple and accessible procedure of capillary force LBL (CF-LBL) assembly to build microstrips of thin films at sufficiently high throughput and low cost. Two examples are discussed as follows: 1) pH-dependent thickness behavior of sequentially adsorbed layers of weak polyelectrolytes, and 2) development and investigation of LBL film libraries for the delivery of DNA and RNAi from surfaces. Furthermore, we are in the process of developing this CF-LBL system into a fully programmable and automated platform by using computer-assisted liquid handling robot.