Artificial phototactic swimmer: towards programmable nanomotor

Abstract

Phototactic behavior is commonly observed in motile photosynthetic microorganisms. It is desirable to create an artificial nanorobotic system to mimic the behavior of the motile bacterial for varieties of applications such as non-invasive microsurgery and targeted active drug delivery. Previously, it has been observed that asymmetric redox reaction on bi-metallic nanowire can produce electric field and propel itself in solution. This autonomous motion shows that artificial inorganic nanomaterial can be used as nanomotor which harvest energy from environment. Here, we will present a rational designed nanomotor system based on nanotree which harvest energy from absorbed photons by photoeletrochemical (PEC) reaction. In this design, we focus on controllability and programmability of nanomotor. The Individual Janus nanotree is designed that it can sense the direction of light vector and direct to illumination direction. Furthermore, by proper chemical modification, we can program our Janus nanotrees to show either migrates towards light source or away from light source. We will also discuss about the group schooling behaviors of nanomotor in our design.