Integrating Synthetic Cells and Soft Materials for a Biosensing Soft Robot

Replicating integrated functions of biological systems across different length-scales is an ultimate goal in the engineering of biomimetic systems. To this end, the integration of synthetic biological systems and soft robots has the potential to increase sensory and control capabilities of biomimetic devices. However, it remains difficult to implement the interface between soft materials and synthetic cells. Here, we have integrated these fields through constructing a hybrid device that consists of soft materials, synthetic bacteria, fluidic systems and electronics toward creating a multi-input soft robotic system that has biosensing capabilities. Specifically our device consists of a series of circular wells and channels patterned into a flexible polydimethylsiloxane (PDMS) layer for culturing synthetic Escherichia coli that express green fluorescent proteins (GFP). This is coupled with an electronic layer housing an LED circuit designed to excite the GFP within the biomaterial layer. The PDMS chamber has high translucence that allows for optical control of synthetic bacteria, and high viscoelasticity that provides mechanical versatility, allowing it to function within a pneumatically actuated soft machine when sealed within a permeable flexible membrane. We further have also shown the ability to use this with an optogenetic genetic construct within the bacteria, which produces GFP in the presence of a chemical inducer and ceases production through blue light excitation. We believe that our work will have a wide impact on the development of the next-generation bio-opto-fluidic devices and the integration of synthetic biological systems with soft electronic materials.