Enhanced solvent resistance and electrical performance of electrohydrodynamic jet printed PEDOT:PSS composite patterns: effects of hardeners on the performance of organic thin-film transistors

Fiber-Type Transistor-Based Chemical and Physical Sensors Using Conjugated Polymers

Fiber-type electronics is a crucial field for realizing wearable electronic devices with a wide range of sensing applications. In this paper, we begin by discussing the fabrication of fibers from conjugated polymers. We then explore the utilization of these fibers in the development of field-effect and electrochemical transistors. Finally, we investigate the diverse applications of these fiber-type transistors, encompassing chemical and physical sensors. Our paper aims to offer a comprehensive understanding of the use of conjugated polymers in fiber-type transistor-based sensors.

Review on PEDOT:PSS-Based Conductive Fabric

This article reviews conductive fabrics made with the conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), their fabrication techniques, and their applications. PEDOT:PSS has attracted interest in smart textile technology due to its relatively high electrical conductivity, water dispersibility, ease of manufacturing, environmental stability, and commercial availability. Several methods apply PEDOT:PSS to textiles. They include polymerization of the monomer, coating, dyeing, and printing methods. In addition, several studies have shown the conductivity of fabrics with the addition of PEDOT:PSS. The electrical properties of conductive textiles with a certain sheet resistance can be reduced by several orders of magnitude using PEDOT:PSS and polar solvents as secondary dopants. In addition, several studies have shown that the flexibility and durability of textiles coated with PEDOT:PSS can be improved by creating a composite with other polymers, such as polyurethane, which has high flexibility and extensibility. This improvement is due to the stronger bonding of PEDOT:PSS to the fabrics. Sensors, actuators, antennas, interconnectors, energy harvesting, and storage devices have been developed with PEDOT:PSS-based conductive fabrics.

High Precision 3D Printing for Micro to Nano Scale Biomedical and Electronic Devices

Three dimensional printing (3DP), or additive manufacturing, is an exponentially growing process in the fabrication of various technologies with applications in sectors such as electronics, biomedical, pharmaceutical and tissue engineering. Micro and nano scale printing is encouraging the innovation of the aforementioned sectors, due to the ability to control design, material and chemical properties at a highly precise level, which is advantageous in creating a high surface area to volume ratio and altering the overall products’ mechanical and physical properties. In this review, micro/-nano printing technology, mainly related to lithography, inkjet and electrohydrodynamic (EHD) printing and their biomedical and electronic applications will be discussed. The current limitations to micro/-nano printing methods will be examined, covering the difficulty in achieving controlled structures at the miniscule micro and nano scale required for specific applications.

Direct Printing of Asymmetric Electrodes for Improving Charge Injection/Extraction in Organic Electronics

Engineering the energy levels of organic conducting materials can be useful for developing high-performance organic field-effect transistors (OFETs), whose electrodes must be well controlled to facilitate easy charge carrier transport from the source to drain through an active channel. However, symmetric source and drain electrodes that have the same energy levels are inevitably unfavorable for either charge injection or charge extraction. In this study, asymmetric source and drain electrodes are simply prepared using the electrohydrodynamic (EHD)-jet printing technique after the careful work function engineering of organic conducting material composites. Two types of additives effectively tune the energy levels of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate-based composites. These solutions are alternately patterned using the EHD-jet printing process, where the use of an electric field makes fine jet control that enables to directly print asymmetric electrodes. The asymmetric combination of EHD-printed electrodes helps in obtaining advanced charge transport properties in p-type and n-type OFETs, as well as their organic complementary inverters. This strategy is believed to provide useful guidelines for the facile patterning of asymmetric electrodes, enabling the desirable properties of charge injection and extraction to be achieved in organic electronic devices.