by A team of researchers from Korea and the U.K. has embarked on a study to better understand the molecular orientation-dependent transient behaviors of organic mixed ionic–electronic conductors (OMIECs). OMIECs are highly sought-after materials for various applications, such as bioelectronics, neuromorphic computing, and bio-fuel cells, due to their combined electronic and ionic conduction properties. In order to further enhance the potential of these materials, there is a need to diversify their properties and develop techniques for tailoring OMIEC-based devices based on specific application requirements.
The team, led by Professor Myung-Han Yoon from the School of Materials Science and Engineering at Gwangju Institute of Science and Technology, aimed to bridge the existing gap in the understanding of transient behaviors of OMIECs governed by variations in molecular orientation. Their study, published in Nature Communications on November 28, 2023, focused on the investigation of these behaviors using an organic electrochemical transistor (OECT).
Previous studies have already explored OMIECs using the OECT platform, suggesting that factors such as direction, length, side chain symmetry, polymer backbone structure, and film crystallinity influence the properties of OECTs. OECTs have the potential to mimic the computing mechanisms of neurons and synapses in spiking neural networks (SNNs), making them a promising technology. The researchers sought to investigate the correlation between backbone planarity-dependent molecular orientation and transient characteristics of OECTs.
To conduct their study, the researchers synthesized two new 1,4-dithienylphenylene (DTP)-based OMIECs, called DTP-2T and DTP-P. These polymers had the same ionic and electronic properties, but differed in molecular orientation, allowing the researchers to control the dominant molecular orientation of the mixed conductor system by manipulating the polymer backbone planarity. OECT devices were then fabricated using the DTP polymer and subjected to electrochemical analysis.
The initial findings indicated that both polymers exhibited similar electrochemical properties despite their different molecular orientations. However, when the researchers changed the ion injection direction at a certain current/voltage during the analysis, they observed that the ion injection direction relative to the molecular orientation affected the length of the ion drift pathway. This, in turn, indirectly influenced the ion mobility within the polymers and resulted in unique transient responses in OECT devices.
The findings of this study offer a new perspective on the molecular orientation-dependent characteristics of OECT devices. OECT-based SNN architectures hold the potential to replace current computing systems by increasing computation speed and reducing energy consumption. The researchers believe that their findings will contribute to the realization of SNN-based computing systems in the future. Additionally, the insights gained from this study could aid in the design and development of advanced organic mixed conductor materials for biomolecular and biosignal sensors.
In summary, this research provides valuable insights into the transient behaviors of organic electrochemical transistors governed by molecular orientation. The study opens up avenues for further exploration and application of OMIECs in various fields, offering potential advancements in technology and bioengineering.
Note:
1. Source: Coherent Market Insights, Public sources, Desk research
2. We have leveraged AI tools to mine information and compile it
