(285c) Multiphoton Lithography of Organic Semiconductor Devices for 3D Printing of Flexible Electronic Circuits, Biosensors, and Bioelectronics

In recent years, 3D printing of electronics have received growing attention due to their
potential applications in emerging fields such as nanoelectronics and nanophotonics.
Multiphoton lithography (MPL) is considered the state-of-the-art amongst the microfabrication
techniques with true 3D fabrication capability owing to its excellent level of spatial and temporal
control. Here we introduce a homogenous and transparent photosensitive resin doped with an
organic semiconductor material (OS) compatible with MPL process to fabricate variety of 3D
OS composite microstructures (OSCMs) and microelectronic devices. Inclusion of 0.5 wt% OS
in the resin enhanced the electrical conductivity of the composite polymer about 10 orders of
magnitude and compared to other MPL-based methods, the resultant OSCMs offered high
specific electrical conductivity. As a model protein, laminin was incorporated into these OSCMs
without a significant loss of activity. The OSCMs were biocompatible and supported cell
adhesion and growth. Glucose oxidase encapsulated OSCMs offered a highly sensitive glucose
sensing platform with nearly 10-fold higher sensitivity compared to previous glucose biosensors.
In addition, this biosensor exhibited excellent specificity and high reproducibility. Overall, these
results demonstrate the great potential of these novel MPL-fabricated OSCM devices for a range
of applications from flexible bioelectronics/biosensors, to nanoelectronics and organ-on-a-chip
devices.