Inkjet Printing of Bioresorbable Materials for Manufacturing Transient Microelectronic Devices

Abstract

Herein, the inkjet printing of bioresorbable materials tuned to function as electrode, dielectric, and semiconductor layers is reported, thereby developing multilayered microelectronic devices such as capacitors and thin-film transistors, potentially applicable to address specific medical needs. Polymers and natural materials, e.g., poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), shellac, and β-carotene, indigo inks are implemented using jettable formulations, that are either commercially procured or self-formulated, designed explicitly to deposit fundamental layers for capacitors and transistors. Several parameters are evaluated and adjusted to precisely define a layer's thickness, topology, and geometry, matching with the properties of a fully biodegradable Ormocere substrate, explicitly developed for the specific biological applications. Furthermore, these parameters support in acquiring the intended electrical properties of layers, i.e., conductivity, insulation, semiconductivity, capacitance, and current versus voltage characteristics. The entire manufacturing process of devices is accomplished on the Ormocere substrate under ambient conditions and below 60 °C. The results exhibit that the electrical characteristics of the printed functional layers and devices show direct influence to the physical geometry of the printed features. A fully printed capacitor demonstrates capacitance of 1 nF cm−2, whereas transistors show p-type and n-type characteristics with current 0.18–5 μA and mobility 6 × 10−4–7 × 10−2 cm2 V−1 s−1.