Biomaterial-Based Sensing Inks for Printing
The present disclosure provides, among other things, biopolymer-based ink compositions for printing applications and the converting inert substrates into interactive and responsive interfaces.
Screen-printing and inkjet printing are two techniques that are simple, robust, and allow contemporary deposition and patterning of inks onto substrates. Screen-printing is based on the use of a designed mesh masked with a pattern transferred to the underlying substrate by applying pressure with a squeegee that releases the ink through the designed mesh. It is a robust, fast, and scaled-up process for mass production, however, significant technological gaps are still observable in all production phases, especially in the development and post-processing of the screen-printed materials (e.g., UV curing, temperature annealing in the range of 120-180 °C). Recent research on screen-printing inks has mainly focused on the implementation and improvement of conductive pastes based on fillers, such as silver nanoparticles or carbon-based materials, as part of low-cost solar cells, organic light emitting diodes and wearable electrochemical devices. These inks are mostly based on synthetic polymers and ceramics processed using organic solvents that hamper the addition of active fillers (e.g., chromophores, biological molecules like enzymes and antibodies) to implement sensing devices in a single step that can be pervasively transferred onto multiple surfaces.
Piezoelectric-driven inkjet printing, on the other hand, does not require masking equipment and is generally tailored to achieve smaller resolutions. Specifically, it allows direct transfer of features with sizes in the order of tens of micrometers through drop-by-drop delivery of functionalized inks. Low material consumption, versatility, and compatibility in both ink composition and typology of substrate, enable the maskless inkjet printing technique to be applied not only within the organic electronics field, but also in the making of biochemical sensors and inducing cell alignment in tissue engineering to manufacture interactive interfaces. In addition, digital manipulation of all inkjet printing process steps enables precise droplet-size deposition and reproducible product performance, rendering inkjet printing as a potential tool for implementing in-situ chemical reactions (i.e., Reactive Inkjet printing (RIJ)) with increased yields, but decreased material consumption for device manufacturing and modification of biomaterials.
The restricted size (i.e., depending on the nozzle) of the active molecule to be transferred, the limited rheology (i.e., viscosity) of the material to be printed, and the eventual high volatility of the solvents used, are the main drawbacks that hamper a widespread diffusion of screen and ink-jet printing. Currently, there remains a need in both analog (screen) and digital (inkjet) printing for the development of a biocompatible, printable, and tunable composition that addresses the aforementioned drawbacks.
IP STATUS US Provisional Patent Application 62/867,164 filed 6/26/2019