Organic electrochemical transistors (OECTs) have been revived as potentially versatile platforms for bioelectronic applications due to their high transconductance, direct ionic-electronic coupling, and unique form factors. This perceived applicability to bioelectronics can be attributed to the incorporation of organic mixed conductors that facilitate both ionic and electronic transport, enabling material-inherent translation from biological signals to abiotic readouts. In the past decade, multiple synthetic breakthroughs have yielded channel materials that exhibit significant hole/electron transport while displaying electroactivity in aqueous media. Yet, implicit in the rationale of OECTs as bioelectronic devices is they can be fabricated to be mechanically compatible with biological systems, even though unified guidelines for deformable OECTs remain unclear. In this Perspective, we highlight recent advances for imparting deformability. Specifically, materials selection, design, and chemistry for integral parts of the transistor – substrate, electrolyte, interconnects, and (polymeric) channel materials—will be discussed in the context of benchmarks set by select bioelectronics applications. We conclude by identifying key areas for future research towards mechanically compliant OECTs.
This content will become publicly available on May 17, 2023
Influence of the molecular weight and size distribution of PSS on mixed ionic-electronic transport in PEDOT:PSS
The commercially available polyelectrolyte complex poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is ubiquitous in organic and hybrid electronics. As such, it has often been used as a benchmark material for fundamental studies and the development of new electronic devices. Yet, most studies on PEDOT:PSS have focused on its electronic conductivity in dry environments, with less consideration given to its ion transport, coupled ionic-electronic transport, and charge storage properties in aqueous environments. These properties are essential for applications in bioelectronics (sensors, actuators), charge storage devices, and electrochromic displays. Importantly, past studies on mixed ionic-electronic transport in PEDOT:PSS neglected to consider how the molecular structure of PSS affects mixed ionic-electronic transport. Herein, we therefore investigated the effect of the molecular weight and size distribution of PSS on the electronic properties and morphology of PEDOT:PSS both in dry and aqueous environments, and overall performance in organic electrochemical transistors (OECTs). Using reversible addition–fragmentation chain transfer (RAFT) polymerization with two different chain transfer agents, six PSS samples with monomodal, narrow ( Đ = 1.1) and broad ( Đ = 1.7) size distributions and varying molecular weights were synthesized and used as matrices for PEDOT. We found that using higher molecular weight of PSS ( M n = 145 more »
- Award ID(s):
- 1751308
- Publication Date:
- NSF-PAR ID:
- 10329071
- Journal Name:
- Polymer Chemistry
- Volume:
- 13
- Issue:
- 19
- Page Range or eLocation-ID:
- 2764 to 2775
- ISSN:
- 1759-9954
- Sponsoring Org:
- National Science Foundation
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