Advances in Screen Printing of Conductive Nanomaterials for Stretchable Electronics

Abstract

Stretchable electronics have demonstrated tremendous potential in wearable healthcare, advanced diagnostics, soft robotics, and persistent human–machine interfaces. Still, their applicability is limited by a reliance on low-throughput, high-cost fabrication methods. Traditional MEMS/NEMS metallization and off-contact direct-printing methods are not suitable at scale. In contrast, screen printing is a high-throughput, mature printing method. The recent development of conductive nanomaterial inks that are intrinsically stretchable provides an exciting opportunity for scalable fabrication of stretchable electronics. The design of screen-printed inks is constrained by strict rheological requirements during printing, substrate–ink attraction, and nanomaterial properties that determine dispersibility and percolation threshold. Here, this review provides a concise overview of these key constraints and a recent attempt to meet them. We begin with a description of the fluid dynamics governing screen printing, deduce from these properties the optimal ink rheological properties, and then describe how nanomaterials, solvents, binders, and rheological agents are combined to produce high-performing inks. Although this review emphasizes conductive interconnections, these methods are highly applicable to sensing, insulating, photovoltaic, and semiconducting materials. Finally, we conclude with a discussion on the future opportunities and challenges in screen-printing stretchable electronics and their broader applicability.

Recent Advances in Printing Technologies of Nanomaterials for Implantable Wireless Systems in Health Monitoring and Diagnosis

“…Screen printing, also known as stencil printing, is one of the mature printing technologies and is versatile with high‐throughput and economical cost. [ 50 ] A mask, or stencil, with patterned features is used to define the geometry of the printed pattern. The printing ink is transferred with a squeegee through the stencil openings to the substrate beneath it.…”

“…However, the scope is narrowed to manufacturing technologies. [ 44–50 ] In this review, we provide a more selective scope by focusing on recent advancements in nanomaterials and printing technologies aimed toward wireless implantable devices. Nanomaterials are summarized with a focus on essential characteristics and requirements for implantable concerns.…”

Recent Advances in High-Throughput Nanomaterial Manufacturing for Hybrid Flexible Bioelectronics

“…Screen printing is an ancient printing method that has been employed in garment processing for centuries [ 19 ]. Today, it is a mature industrial process used in textiles, graphics, printed circuit silkscreens, in-mold electronics, capacitive touch sensors, printed heaters, and chemical sensors [ 47 ].…”

“…Fully printed electronics methods have gained significant interest in recent years because they are cheaper, more efficient, and more scalable than traditional MEMS/NEMS processes and capable of direct printing on many flexible and stretchable substrates, such as polyethylene terephthalate (PET), polyimide (PI), polydimethylsiloxane (PDMS), thermoplastic polyurethane (TPU) and paper [ 17 , 18 , 19 ]. However, these approaches are also limited by product throughputs and yields, making it very difficult to manufacture hybrid devices in a manner that would allow for their mass adoption [ 17 ].…”

Screen Printing Carbon Nanotubes Textiles Antennas for Smart Wearables

“…Screen printing is the most common and straightforward conventional printing method, being relatively effortless, versatile, affordable, fast, and adaptable [ 15 , 18 , 19 , 20 ]. Screen printing is a making method that allows transferring the ink through a stencil design to a flat surface by using a squeegee and mesh screen usually made from silk or nylon.…”