Integrating Synthetic Cells and Flexible Electronics for the Control of Bio-Opto-Fluidic Materials

Abstract

The integration of optofluidics and soft materials has ushered in a new generation of flexible devices for drug delivery, biosensors, and tissue engineering. These devices are biocompatible and allow complex control of device dynamics using fluidic and pneumatic controls. Importantly, these devices could be combined with synthetic biological systems to increase sensory and control capabilities of the devices through exploitation of complex genetic controls in synthetic cells. Here, we take the first step towards such bio-opto-fluidic systems by constructing a hybrid device that consists of soft materials, synthetic bacteria, fluidic systems and electronics. Specifically our device consists of a flexible polydimethylsiloxane (PDMS) chamber for culturing synthetic Escherichia coli that express green fluorescent proteins (GFP) and a flexible electronic layer housing an LED with an emission spectrum peak at 395 nm. The PDMS chamber has high gas permeability that facilitates aerobic cell growth conditions, high translucence that allows for optical control of the synthetic bacteria, and high viscoelasticity that provides mechanical versatility. We demonstrated that the synthetically modified bacteria can be excited internally by an electronic component without sacrificing the flexibility and transparency of the device. We have also shown that isopropyl β-D-1-thiogalactopyranoside (IPTG) can be delivered via micro channels over a flexible micro-porous PDMS membrane to modulate gene expression of the synthetically modified bacteria inside the device. Furthermore we optimized the geometry of the device with respect to bacterial growth rates, fluorescence expression, and fluid flow properties. Finally, we tested the device during mechanical deformation by bending to demonstrate the robust function of the device in strain-induced conditions. Our work will have wide impact on the development of the next-generation bio-opto-fluidic devices and the integration of synthetic biological systems with soft electronic materials.