High-Yield Production of Aqueous Graphene for Electrohydrodynamic Drop-on-Demand Printing of Biocompatible Conductive Patterns

Abstract

Presented here is a scalable and aqueous phase exfoliation of graphite to high yield and quality of few layer graphene (FLG) using Bovine Serum Albomine (BSA) and wet ball milling. The produced graphene ink is tailored for printable and flexible electronics, having shown promising results in terms of electrical conductivity and temporal stability. Shear force generated by steel balls which resulted in 2–3 layer defect-free graphene platelets with an average size of hundreds of nm, and with a concentration of about 5.1 mg/mL characterized by Raman spectroscopy, atomic force microscopy (AFM), transmittance electron microscopy (TEM) and UV-vis spectroscopy. Further, a conductive ink was prepared and printed on flexible substrate (Polyimide) with controlled resolution. Scanning electron microscopy (SEM) and Profilometry revealed the effect of thermal annealing on the prints to concede consistent morphological characteristics. The resulted sheet resistance was measured to be R s = 36.75 Ω / sqr for prints as long as 100 mm. Printable inks were produced in volumes ranging from 20 mL to 1 L, with potential to facilitate large scale production of graphene for applications in biosensors, as well as flexible and printable electronics.

3D Printing Technologies in Biosensors Production: Recent Developments

“…In this study, the pivotal role played by both the printing mechanism and the resulting structural and functional properties of the biomolecules involved on the final performance of the biosensor was demonstrated [33]. Asli et al [34] presented a study where graphene was used as ink for a "drop-on-demand" 3D inkjet printer. This technology was employed in order to overcome the print instability issue relying on a time-saving process.…”

“…Intriguingly, 3D geometry can add an unknown physiologically relevant aspect compared with 2D [74]. Mainly in the biosensing field, but not only, the inkjet 3D printing techniques such as direct ink writing (DIW) and drop-on-demand (DOD), have also been widely employed for the fabrication of biosensors due to their advantages of contactless printing, reduction in waste, and rapid deposition [25,33,34,39]. Inkjet printing technology has been used by Mojena-Medina et al [25] to fabricate interdigitated-electrode sensors (IDEs) to monitor epithelial cell cultures.…”

3D Printing‐Enabled Nanoparticle Alignment: A Review of Mechanisms and Applications

“…The sensing enhance ment is due to enlarged surface exposure of the porous wire structures. Other nanoparticles aligned by EHD include the stainless steel particles and rods, [230] micronano aluminum particles, [231] quantum dots, [232] Janus particles, [233] CNTs, [234] graphene, [235] graphene oxide (GO). [236] The EHD method showed the ability to assemble nano particles with regular patterns and the control of polymer mor phologies.…”

Protein-assisted scalable mechanochemical exfoliation of few-layer biocompatible graphene nanosheets

“…Despite being the thinnest material present, it has a Young's modulus of approximately 1 TPa making it stronger than steel [7,8]. A variety of fields including biology [9][10][11] and medicine have begun tapping into the immense potential that graphene presents. For example, He et al [12] used graphene as a surface-enhanced Raman scattering (SERS) substrate in order to carry out multiplex DNA detection.…”