@article{burgt_krauhausen_griggs_mcculloch_toonder_gkoupidenis_2024, title={Bio-inspired multimodal learning with organic neuromorphic electronics for behavioral conditioning in robotics}, url={https://doi.org/10.21203/rs.3.rs-3878146/v1}, DOI={10.21203/rs.3.rs-3878146/v1}, abstractNote={Abstract}, author={Burgt, Yoeri and Krauhausen, Imke and Griggs, Sophie and McCulloch, Iain and Toonder, Jaap and Gkoupidenis, Paschalis}, year={2024}, month={Jan} }
 @article{colucci_koutsouras_morsbach_gkoupidenis_blom_kraft_2024, title={Organic Electrochemical Transistor-Based Immunosensors for SARS-CoV-2 Detection}, url={https://doi.org/10.1021/acsaelm.4c00260}, DOI={10.1021/acsaelm.4c00260}, abstractNote={Following the emergence of the worldwide severe respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the need for innovative strategies and methodologies to facilitate cost-effective and early stage diagnosis has become evident. To prevent the outbreak of such contagious diseases, an efficient approach is systematic testing of the population. Here, we introduce a planar organic electrochemical transistor (OECT)-based immunosensor for the detection of SARS-CoV-2. The gold gate electrode of the poly(3,4-ethylenedioxy-thiophene):polystyrene sulfonate (PEDOT:PSS)-based OECTs was functionalized with SARS-CoV-2 antibodies. The detection mechanism is based on the specific interaction of the antibodies with the spike protein of the virus, allowing its direct detection and not requiring the prior formation of antibodies in the patient's body. As a proof of concept, the ability of the immunosensor to detect the SARS-CoV-2 spike protein is assessed. The sensor exhibits a remarkably low limit of detection (LOD) of 10–17 M, with an incubation time of 30 min. Furthermore, the sensors demonstrate selectivity when exposed to similar proteins and stability, retaining their LOD after 20 days of storage. Lastly, the functionalization protocol may easily be adapted for other pathogens/biomarkers, enabling not only a point-of-care device for SARS-CoV-2 detection but also a versatile platform for biosensing applications.}, journal={ACS Applied Electronic Materials}, author={Colucci, Renan and Koutsouras, Dimitrios A. and Morsbach, Svenja and Gkoupidenis, Paschalis and Blom, Paul W. M. and Kraft, Ulrike}, year={2024}, month={Apr} }
 @article{shao_li_yang_he_wang_fu_fu_ling_gkoupidenis_yan_et al._2023, title={A Reconfigurable Optoelectronic Synaptic Transistor with Stable Zr‐CsPbI<sub>3</sub> Nanocrystals for Visuomorphic Computing}, volume={35}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.202208497}, DOI={10.1002/adma.202208497}, abstractNote={Abstract}, number={12}, journal={Advanced Materials}, publisher={Wiley}, author={Shao, He and Li, Yueqing and Yang, Wei and He, Xiang and Wang, Le and Fu, Jingwei and Fu, Mingyang and Ling, Haifeng and Gkoupidenis, Paschalis and Yan, Feng and et al.}, year={2023}, month={Feb} }
 @article{krauhausen_coen_spolaor_gkoupidenis_van de burgt_2023, title={Brain‐Inspired Organic Electronics: Merging Neuromorphic Computing and Bioelectronics Using Conductive Polymers}, volume={10}, ISSN={1616-301X 1616-3028}, url={http://dx.doi.org/10.1002/adfm.202307729}, DOI={10.1002/adfm.202307729}, abstractNote={Abstract}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Krauhausen, Imke and Coen, Charles‐Théophile and Spolaor, Simone and Gkoupidenis, Paschalis and van de Burgt, Yoeri}, year={2023}, month={Oct} }
 @article{tzouvadaki_gkoupidenis_vassanelli_wang_prodromakis_2023, title={Interfacing Biology and Electronics with Memristive Materials}, url={https://doi.org/10.1002/adma.202210035}, DOI={10.1002/adma.202210035}, abstractNote={Abstract}, journal={Advanced Materials}, author={Tzouvadaki, Ioulia and Gkoupidenis, Paschalis and Vassanelli, Stefano and Wang, Shiwei and Prodromakis, Themis}, year={2023}, month={Aug} }
 @article{cucchi_parker_stavrinidou_gkoupidenis_kleemann_2023, title={In Liquido Computation with Electrochemical Transistors and Mixed Conductors for Intelligent Bioelectronics}, volume={2}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.202209516}, DOI={10.1002/adma.202209516}, abstractNote={Next‐generation implantable computational devices require long‐term‐stable electronic components capable of operating in, and interacting with, electrolytic surroundings without being damaged. Organic electrochemical transistors (OECTs) emerged as fitting candidates. However, while single devices feature impressive figures of merit, integrated circuits (ICs) immersed in common electrolytes are hard to realize using electrochemical transistors, and there is no clear path forward for optimal top‐down circuit design and high‐density integration. The simple observation that two OECTs immersed in the same electrolytic medium will inevitably interact hampers their implementation in complex circuitry. The electrolyte's ionic conductivity connects all the devices in the liquid, producing unwanted and often unforeseeable dynamics. Minimizing or harnessing this crosstalk has been the focus of very recent studies. Herein, the main challenges, trends, and opportunities for realizing OECT‐based circuitry in a liquid environment that could circumnavigate the hard limits of engineering and human physiology, are discussed. The most successful approaches in autonomous bioelectronics and information processing are analyzed. Elaborating on the strategies to circumvent and harness device crosstalk proves that platforms capable of complex computation and even machine learning (ML) can be realized in liquido using mixed ionic–electronic conductors (OMIECs).}, journal={Advanced Materials}, publisher={Wiley}, author={Cucchi, Matteo and Parker, Daniela and Stavrinidou, Eleni and Gkoupidenis, Paschalis and Kleemann, Hans}, year={2023}, month={Feb}, pages={2209516} }
 @article{gkoupidenis_zhang_kleemann_ling_santoro_fabiano_salleo_burgt_2023, title={Organic mixed conductors for bioinspired electronics}, url={https://doi.org/10.1038/s41578-023-00622-5}, DOI={10.1038/s41578-023-00622-5}, journal={Nature Reviews Materials}, author={Gkoupidenis, P. and Zhang, Y. and Kleemann, H. and Ling, H. and Santoro, F. and Fabiano, S. and Salleo, A. and Burgt, Y.}, year={2023}, month={Dec} }
 @article{lieberth_pavlou_harig_blom_gkoupidenis_torricelli_2023, title={Real‐Time Monitoring of Cellular Barrier Functionality with Dynamic‐Mode Current‐Driven Organic Electrochemical Transistor}, volume={8}, ISSN={2365-709X 2365-709X}, url={http://dx.doi.org/10.1002/admt.202201697}, DOI={10.1002/admt.202201697}, abstractNote={Abstract}, number={10}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Lieberth, Katharina and Pavlou, Aristea and Harig, Daria and Blom, Paul W. M. and Gkoupidenis, Paschalis and Torricelli, Fabrizio}, year={2023}, month={Feb} }
 @article{zhu_li_yelemulati_deng_li_wang_li_li_gkoupidenis_tai_2022, title={An artificial remote tactile device with 3D depth-of-field sensation}, url={https://doi.org/10.1126/sciadv.abo5314}, DOI={10.1126/sciadv.abo5314}, abstractNote={Flexible tactile neuromorphic devices are becoming important as the impetus for the development of human-machine collaboration. However, accomplishing and further transcending human intelligence with artificial intelligence still confront many barriers. Here, we present a self-powered stretchable three-dimensional remote tactile device (3D-RTD) that performs the depth-of-field (DOF) sensation of external mechanical motions through a conductive-dielectric heterogeneous structure. The device can build a logic relationship precisely between DOF motions of an external active object and sensory potential signals of bipolar sign, frequency, amplitude, etc. The sensory mechanism is revealed on the basis of the electrostatic theory and multiphysics modeling, and the performance is verified via an artificial-biological hybrid system with micro/macroscale interaction. The feasibility of the 3D-RTD as an obstacle-avoidance patch for the blind is systematically demonstrated with a rat. This work paves the way for multimodal neuromorphic device that transcends the function of a biological one toward a new modality for brain-like intelligence.}, journal={Science Advances}, author={Zhu, Shanshan and Li, Yuanheng and Yelemulati, Huoerhute and Deng, Xinping and Li, Yongcheng and Wang, Jingjing and Li, Xiaojian and Li, Guanglin and Gkoupidenis, Paschalis and Tai, Yanlong}, year={2022}, month={Oct} }
 @article{sarkar_lieberth_pavlou_frank_mailaender_mcculloch_blom_torricelli_gkoupidenis_2022, title={An organic artificial spiking neuron for in situ neuromorphic sensing and biointerfacing}, url={https://doi.org/10.1038/s41928-022-00859-y}, DOI={10.1038/s41928-022-00859-y}, abstractNote={Abstract}, journal={Nature Electronics}, author={Sarkar, Tanmoy and Lieberth, Katharina and Pavlou, Aristea and Frank, Thomas and Mailaender, Volker and McCulloch, Iain and Blom, Paul W. M. and Torricelli, Fabrizio and Gkoupidenis, Paschalis}, year={2022}, month={Nov} }
 @article{artificial neurons emulate biological counterparts to enable synergetic operation_2022, volume={5}, ISSN={2520-1131}, url={http://dx.doi.org/10.1038/s41928-022-00862-3}, DOI={10.1038/s41928-022-00862-3}, number={11}, journal={Nature Electronics}, publisher={Springer Science and Business Media LLC}, year={2022}, month={Nov}, pages={721–722} }
 @article{granelli_alessandri_gkoupidenis_vassalini_kovács‐vajna_blom_torricelli_2022, title={High‐Performance Bioelectronic Circuits Integrated on Biodegradable and Compostable Substrates with Fully Printed Mask‐Less Organic Electrochemical Transistors}, volume={18}, ISSN={1613-6810 1613-6829}, url={http://dx.doi.org/10.1002/smll.202108077}, DOI={10.1002/smll.202108077}, abstractNote={Abstract}, number={26}, journal={Small}, publisher={Wiley}, author={Granelli, Roberto and Alessandri, Ivano and Gkoupidenis, Paschalis and Vassalini, Irene and Kovács‐Vajna, Zsolt M. and Blom, Paul W. M. and Torricelli, Fabrizio}, year={2022}, month={Jun} }
 @article{zhang_ye_van der pol_dong_van doremaele_krauhausen_liu_gkoupidenis_portale_song_et al._2022, title={High‐Performance Organic Electrochemical Transistors and Neuromorphic Devices Comprising Naphthalenediimide‐Dialkoxybithiazole Copolymers Bearing Glycol Ether Pendant Groups}, volume={32}, ISSN={1616-301X 1616-3028}, url={http://dx.doi.org/10.1002/adfm.202201593}, DOI={10.1002/adfm.202201593}, abstractNote={Abstract}, number={27}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Zhang, Yanxi and Ye, Gang and van der Pol, Tom P. A. and Dong, Jingjin and van Doremaele, Eveline R. W. and Krauhausen, Imke and Liu, Yuru and Gkoupidenis, Paschalis and Portale, Giuseppe and Song, Jun and et al.}, year={2022}, month={Apr} }
 @inproceedings{gkoupidenis_2022, title={Organic neuromorphic electronics for bio-inspired processing and local sensorimotor learning in robotics}, url={http://dx.doi.org/10.1117/12.2636040}, DOI={10.1117/12.2636040}, abstractNote={Artificial intelligence applications have demonstrated their enormous potential for complex processing over the last decade. However, they are mainly based on digital operating principles while being part of an analogue world. Moreover, they still lack the efficiency and computing capacity of biological systems. Neuromorphic electronics emulate the analogue information processing of biological nervous systems. Neuromorphic electronics based on organic materials have the ability to emulate efficiently and with fidelity a wide range of bio-inspired functions. A prominent example of a neuromorphic device is based on organic mixed conductors (ionic-electronic). Neuromorphic devices based on organic mixed conductors show volatile, non-volatile and tunable dynamics suitable for the emulation of synaptic plasticity and neuronal functions, and for the mapping of artificial neural networks in physical circuits. Finally, small-scale organic neuromorphic circuits enable the local sensorimotor control and learning in robotics.}, booktitle={Organic and Hybrid Sensors and Bioelectronics XV}, publisher={SPIE}, author={Gkoupidenis, Paschalis}, editor={Shinar, Ruth and Kymissis, Ioannis and List-Kratochvil, Emil J.Editors}, year={2022}, month={Oct} }
 @article{sarkar_lieberth_pavlou_frank_mailaender_mcculloch_blom_torricelli_gkoupidenis_2022, title={Publisher Correction: An organic artificial spiking neuron for in situ neuromorphic sensing and biointerfacing}, url={https://doi.org/10.1038/s41928-022-00894-9}, DOI={10.1038/s41928-022-00894-9}, journal={Nature Electronics}, author={Sarkar, Tanmoy and Lieberth, Katharina and Pavlou, Aristea and Frank, Thomas and Mailaender, Volker and McCulloch, Iain and Blom, Paul W. M. and Torricelli, Fabrizio and Gkoupidenis, Paschalis}, year={2022}, month={Nov} }
 @article{koutsouras_amiri_blom_torricelli_asadi_gkoupidenis_2021, title={An Iontronic Multiplexer Based on Spatiotemporal Dynamics of Multiterminal Organic Electrochemical Transistors}, url={https://doi.org/10.1002/adfm.202011013}, DOI={10.1002/adfm.202011013}, abstractNote={Abstract}, journal={Advanced Functional Materials}, author={Koutsouras, Dimitrios A. and Amiri, Morteza Hassanpour and Blom, Paul W. M. and Torricelli, Fabrizio and Asadi, Kamal and Gkoupidenis, Paschalis}, year={2021}, month={May} }
 @article{seufert_hassanpouramiri_gkoupidenis_asadi_2021, title={Crossbar Array of Artificial Synapses Based on Ferroelectric Diodes}, volume={7}, ISSN={2199-160X 2199-160X}, url={http://dx.doi.org/10.1002/aelm.202100558}, DOI={10.1002/aelm.202100558}, abstractNote={Abstract}, number={12}, journal={Advanced Electronic Materials}, publisher={Wiley}, author={Seufert, Laura and HassanpourAmiri, Morteza and Gkoupidenis, Paschalis and Asadi, Kamal}, year={2021}, month={Oct} }
 @article{lieberth_romele_torricelli_koutsouras_brückner_mailänder_gkoupidenis_blom_2021, title={Current‐Driven Organic Electrochemical Transistors for Monitoring Cell Layer Integrity with Enhanced Sensitivity}, volume={10}, ISSN={2192-2640 2192-2659}, url={http://dx.doi.org/10.1002/adhm.202100845}, DOI={10.1002/adhm.202100845}, abstractNote={Abstract}, number={19}, journal={Advanced Healthcare Materials}, publisher={Wiley}, author={Lieberth, Katharina and Romele, Paolo and Torricelli, Fabrizio and Koutsouras, Dimitrios A. and Brückner, Maximilian and Mailänder, Volker and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2021}, month={Jul} }
 @article{koutsouras_torricelli_gkoupidenis_blom_2021, title={Efficient Gating of Organic Electrochemical Transistors with In‐Plane Gate Electrodes}, volume={6}, ISSN={2365-709X 2365-709X}, url={http://dx.doi.org/10.1002/admt.202100732}, DOI={10.1002/admt.202100732}, abstractNote={Abstract}, number={12}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Koutsouras, Dimitrios A. and Torricelli, Fabrizio and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2021}, month={Aug} }
 @misc{torricelli_romele_gkoupidenis_koutsouras_lieberth_kovács-vajna_blom_2021, title={Integrated amplifier with complementary organic electrochemical transistors for high-sensitivity ion detection and real-time monitoring}, url={http://dx.doi.org/10.1117/12.2583428}, DOI={10.1117/12.2583428}, abstractNote={Ions are fundamental biological regulators enabling the communication between cells, regulating metabolic and bioenergetic processing and playing a key role in pH regulation and hydration. The in-situ quantification of the ion concentration is gathering relevant interest in biomedical diagnostics and healthcare. State-of-art transistor-based ion sensors show an intrinsic trade-off between sensitivity, operating range and supply voltage. To overcome these limitations, here we focus on ion sensor amplifiers where complementary OECTs are integrated in a push-pull configuration, providing sensitivity larger than 1 V/dec at a supply voltage down to 0.5 V and operating in the physiological range. Ion detection over a range of five orders of magnitude and real-time monitoring of variations two orders of magnitude lower than the detected concentration are achieved. The ion-sensitive amplifier sets a new benchmark for ion-sensing devices, opening possibilities for predictive diagnostics and personalized medicine.}, journal={Integrated Sensors for Biological and Neural Sensing}, publisher={SPIE}, author={Torricelli, Fabrizio and Romele, Paolo and Gkoupidenis, Paschalis and Koutsouras, Dimitrios A. and Lieberth, Katharina and Kovács-Vajna, Zsolt M. and Blom, Paul W. M.}, editor={Mohseni, HoomanEditor}, year={2021}, month={Mar} }
 @article{lieberth_brückner_torricelli_mailänder_gkoupidenis_blom_2021, title={Monitoring Reversible Tight Junction Modulation with a Current‐Driven Organic Electrochemical Transistor}, volume={6}, ISSN={2365-709X 2365-709X}, url={http://dx.doi.org/10.1002/admt.202000940}, DOI={10.1002/admt.202000940}, abstractNote={Abstract}, number={5}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Lieberth, Katharina and Brückner, Maximilian and Torricelli, Fabrizio and Mailänder, Volker and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2021}, month={Apr} }
 @misc{keene_gkoupidenis_burgt_2021, title={Neuromorphic computing systems based on flexible organic electronics}, ISBN={9780128188903}, url={http://dx.doi.org/10.1016/b978-0-12-818890-3.00018-7}, DOI={10.1016/b978-0-12-818890-3.00018-7}, abstractNote={Today software systems known as neural networks are at the basis of numerous artificial intelligence applications and are successfully implemented to translate languages, classify images, recognize diseases, and form the basis of the spur in autonomous driving. However, these algorithms require a substantial amount of computer resources and energy. The brain on the other hand, operates in a highly parallel fashion, connecting neurons via synapses, rendering it compact and highly efficient in recognizing patterns, speech, and images. Neuromorphic engineering takes advantage of the efficiency of the brain by mimicking and implementing essential concepts such as neurons and synapses in hardware. In this chapter we review the development of organic neuromorphic devices. We highlight efforts to mimic essential brain functions, such as spiking phenomena, spatiotemporal processing, homeostasis, and functional connectivity and demonstrate related applications. Next, we review important metrics for implementing low-power and reliable neuromorphic computing, such as state retention and conductance tuning. Finally, we give an outlook on future directions and potential applications, with a particular focus on interfacing with biological environments.}, journal={Organic Flexible Electronics}, publisher={Elsevier}, author={Keene, Scott T. and Gkoupidenis, Paschalis and Burgt, Yoeri van de}, year={2021}, pages={531–574} }
 @article{krauhausen_koutsouras_melianas_keene_lieberth_ledanseur_sheelamanthula_giovannitti_torricelli_mcculloch_et al._2021, title={Organic neuromorphic electronics for sensorimotor integration and learning in robotics}, volume={7}, ISSN={2375-2548}, url={http://dx.doi.org/10.1126/sciadv.abl5068}, DOI={10.1126/sciadv.abl5068}, abstractNote={A robot learns to follow a path to exit a maze through sensorimotor learning that is induced by an organic neuromorphic circuit.}, number={50}, journal={Science Advances}, publisher={American Association for the Advancement of Science (AAAS)}, author={Krauhausen, Imke and Koutsouras, Dimitrios A. and Melianas, Armantas and Keene, Scott T. and Lieberth, Katharina and Ledanseur, Hadrien and Sheelamanthula, Rajendar and Giovannitti, Alexander and Torricelli, Fabrizio and Mcculloch, Iain and et al.}, year={2021}, month={Dec} }
 @misc{gkoupidenis_2021, title={Organic neuromorphic electronics: bio-inspired functions and applications}, url={http://dx.doi.org/10.1117/12.2595049}, DOI={10.1117/12.2595049}, abstractNote={The seamless integration of electronics with biology requires new bio-inspired approaches that, analogously to nature, rely on the presence of electrolytes for signal multiplexing. On the contrary, conventional multiplexing schemes mostly rely on electronic carriers and require peripheral circuitry for their implementation, which imposes limitations toward their adoption in bio-applications. Here we show an iontronic multiplexer based on spatiotemporal dynamics of organic electrochemical transistors (OECTs), with an electrolyte as the shared medium of communication. The iontronic system discriminates locally random-access events with no need of peripheral circuitry, thus deceasing significantly the integration complexity. The form factors of OETCs, open new avenues for unconventional multiplexing in the emerging fields of bioelectronics and neuromorphic sensors. Examples of organic neuromorphic electronics for local learning in applications with energy restrictions are also showcased.}, journal={Organic and Hybrid Sensors and Bioelectronics XIV}, publisher={SPIE}, author={Gkoupidenis, Paschalis}, editor={Shinar, Ruth and Kymissis, Ioannis and List-Kratochvil, Emil J.Editors}, year={2021}, month={Aug} }
 @article{koutsouras_lieberth_torricelli_gkoupidenis_blom_2021, title={Selective Ion Detection with Integrated Organic Electrochemical Transistors}, volume={6}, ISSN={2365-709X 2365-709X}, url={http://dx.doi.org/10.1002/admt.202100591}, DOI={10.1002/admt.202100591}, abstractNote={Abstract}, number={12}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Koutsouras, Dimitrios A. and Lieberth, Katharina and Torricelli, Fabrizio and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2021}, month={Aug} }
 @article{jeong_gkoupidenis_asadi_2021, title={Solution‐Processed Perovskite Field‐Effect Transistor Artificial Synapses}, volume={33}, ISSN={0935-9648 1521-4095}, url={http://dx.doi.org/10.1002/adma.202104034}, DOI={10.1002/adma.202104034}, abstractNote={Abstract}, number={52}, journal={Advanced Materials}, publisher={Wiley}, author={Jeong, Beomjin and Gkoupidenis, Paschalis and Asadi, Kamal}, year={2021}, month={Oct} }
 @article{wang_li_wang_xu_fu_liu_lin_ling_gkoupidenis_yi_et al._2021, title={Thin-film transistors for emerging neuromorphic electronics: fundamentals, materials, and pattern recognition}, url={https://doi.org/10.1039/D1TC01660A}, DOI={10.1039/D1TC01660A}, abstractNote={This review paper provides an overview of the recent successful simulation of pattern recognition with TFT-based artificial synapses from device- to system-level.}, journal={Journal of Materials Chemistry C}, publisher={Royal Society of Chemistry (RSC)}, author={Wang, Conglin and Li, Yuanzhe and Wang, Yucong and Xu, Xiangdong and Fu, Mingyang and Liu, Yuyu and Lin, Zongqiong and Ling, Haifeng and Gkoupidenis, Paschalis and Yi, Mingdong and et al.}, year={2021} }
 @article{hassanpour amiri_heidler_müllen_gkoupidenis_asadi_2020, title={Designing Multi‐Level Resistance States in Graphene Ferroelectric Transistors}, volume={30}, ISSN={1616-301X 1616-3028}, url={http://dx.doi.org/10.1002/adfm.202003085}, DOI={10.1002/adfm.202003085}, abstractNote={Abstract}, number={34}, journal={Advanced Functional Materials}, publisher={Wiley}, author={Hassanpour Amiri, Morteza and Heidler, Jonas and Müllen, Klaus and Gkoupidenis, Paschalis and Asadi, Kamal}, year={2020}, month={Jun} }
 @article{ling_koutsouras_kazemzadeh_burgt_yan_gkoupidenis_2020, title={Electrolyte-gated transistors for synaptic electronics, neuromorphic computing, and adaptable biointerfacing}, url={https://doi.org/10.1063/1.5122249}, DOI={10.1063/1.5122249}, abstractNote={Functional emulation of biological synapses using electronic devices is regarded as the first step toward neuromorphic engineering and artificial neural networks (ANNs). Electrolyte-gated transistors (EGTs) are mixed ionic–electronic conductivity devices capable of efficient gate-channel capacitance coupling, biocompatibility, and flexible architectures. Electrolyte gating offers significant advantages for the realization of neuromorphic devices/architectures, including ultralow-voltage operation and the ability to form parallel-interconnected networks with minimal hardwired connectivity. In this review, the most recent developments in EGT-based electronics are introduced with their synaptic behaviors and detailed mechanisms, including short-/long-term plasticity, global regulation phenomena, lateral coupling between device terminals, and spatiotemporal correlated functions. Analog memory phenomena allow for the implementation of perceptron-based ANNs. Due to their mixed-conductivity phenomena, neuromorphic circuits based on EGTs allow for facile interfacing with biological environments. We also discuss the future challenges in implementing low power, high speed, and reliable neuromorphic computing for large-scale ANNs with these neuromorphic devices. The advancement of neuromorphic devices that rely on EGTs highlights the importance of this field for neuromorphic computing and for novel healthcare technologies in the form of adaptable or trainable biointerfacing.}, journal={Applied Physics Reviews}, author={Ling, Haifeng and Koutsouras, Dimitrios A. and Kazemzadeh, Setareh and Burgt, Yoeri and Yan, Feng and Gkoupidenis, Paschalis}, year={2020}, month={Mar} }
 @article{romele_gkoupidenis_koutsouras_lieberth_kovács-vajna_blom_torricelli_2020, title={Multiscale real time and high sensitivity ion detection with complementary organic electrochemical transistors amplifier}, url={https://doi.org/10.1038/s41467-020-17547-0}, DOI={10.1038/s41467-020-17547-0}, abstractNote={Abstract}, journal={Nature Communications}, author={Romele, Paolo and Gkoupidenis, Paschalis and Koutsouras, Dimitrios A. and Lieberth, Katharina and Kovács-Vajna, Zsolt M. and Blom, Paul W. M. and Torricelli, Fabrizio}, year={2020}, month={Jul} }
 @article{van de burgt_gkoupidenis_2020, title={Organic materials and devices for brain-inspired computing: From artificial implementation to biophysical realism}, volume={45}, ISSN={0883-7694 1938-1425}, url={http://dx.doi.org/10.1557/mrs.2020.194}, DOI={10.1557/mrs.2020.194}, abstractNote={Abstract}, number={8}, journal={MRS Bulletin}, publisher={Springer Science and Business Media LLC}, author={van de Burgt, Yoeri and Gkoupidenis, Paschalis}, year={2020}, month={Aug}, pages={631–640} }
 @article{tuchman_mangoma_gkoupidenis_van de burgt_john_mathews_shaheen_daly_malliaras_salleo_2020, title={Organic neuromorphic devices: Past, present, and future challenges}, volume={45}, ISSN={0883-7694 1938-1425}, url={http://dx.doi.org/10.1557/mrs.2020.196}, DOI={10.1557/mrs.2020.196}, abstractNote={Abstract}, number={8}, journal={MRS Bulletin}, publisher={Springer Science and Business Media LLC}, author={Tuchman, Yaakov and Mangoma, Tanyaradzwa N. and Gkoupidenis, Paschalis and van de Burgt, Yoeri and John, Rohit Abraham and Mathews, Nripan and Shaheen, Sean E. and Daly, Ronan and Malliaras, George G. and Salleo, Alberto}, year={2020}, month={Aug}, pages={619–630} }
 @inproceedings{gkoupidenis_2019, title={Biological plausibility in organic neuromorphic devices: from global phenomena to synchronization functions}, url={http://dx.doi.org/10.1117/12.2526392}, DOI={10.1117/12.2526392}, abstractNote={It is now well recognized that traditional computing systems based on von Neumann architecture are not efficient enough to manipulate and process the massive amount of data produced by the contemporary information technologies. A shifting paradigm from the traditional computing systems is the emulation of the brain computational efficiency at the hardware-based level, a field that is also known as neuromorphic computing. Although neuromorphic computing with inorganic materials has been advanced over the past years, nevertheless biological plausibility is questionable in many cases of solid-state technologies. In the brain, for instance, neural populations are immersed in a common electrolyte or cerebrospinal fluid and this fact equips the brain with more efficient features in processing when compared to electronic devices or circuits. Due to this topology in biological neural networks, higher order phenomena exist such as global regulation of neural activity and communication between different regions in the brain mediated by the presence of the global electrolyte. In this work, device concepts will be presented that lead to biological plausibility in organic neuromorphic devices, including global phenomena and synchronization functions. Introducing this level of biological plausibility, paves the way for new concepts of neuromorphic communication between different subunits in a circuit.}, booktitle={Organic and Hybrid Sensors and Bioelectronics XII}, publisher={SPIE}, author={Gkoupidenis, Paschalis}, editor={Shinar, Ruth and Kymissis, Ioannis and List-Kratochvil, Emil J.Editors}, year={2019}, month={Sep} }
 @article{lingstedt_ghittorelli_lu_koutsouras_marszalek_torricelli_crăciun_gkoupidenis_blom_2019, title={Effect of DMSO Solvent Treatments on the Performance of PEDOT:PSS Based Organic Electrochemical Transistors}, volume={5}, ISSN={2199-160X 2199-160X}, url={http://dx.doi.org/10.1002/aelm.201800804}, DOI={10.1002/aelm.201800804}, abstractNote={Abstract}, number={3}, journal={Advanced Electronic Materials}, publisher={Wiley}, author={Lingstedt, Leona V. and Ghittorelli, Matteo and Lu, Hao and Koutsouras, Dimitrios A. and Marszalek, Tomasz and Torricelli, Fabrizio and Crăciun, N. Irina and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2019}, month={Feb} }
 @article{koutsouras_prodromakis_malliaras_blom_gkoupidenis_2019, title={Functional Connectivity of Organic Neuromorphic Devices by Global Voltage Oscillations}, url={https://doi.org/10.1002/aisy.201900013}, DOI={10.1002/aisy.201900013}, abstractNote={Global oscillations in the brain synchronize neural populations and lead to dynamic binding between different regions. This functional connectivity reconfigures as needed for the architecture of the neural network, thereby transcending the limitations of its hardwired structure. Despite the fact that it underlies the versatility of biological computational systems, this concept is not captured in current neuromorphic device architectures. Herein, functional connectivity in an array of organic neuromorphic devices connected through an electrolyte is demonstrated. The output of these devices is shown to be synchronized by a global oscillatory input despite the fact that individual inputs are stochastic and independent. This temporal coupling is induced at a specific phase of the global oscillation in a way that is reminiscent of phase locking of neurons to brain oscillations. This demonstration provides a pathway toward new neuromorphic architectural paradigms, where dynamic binding transcends the limitations of structural connectivity, and could enable architectural concepts of hierarchical information flow.}, journal={Advanced Intelligent Systems}, author={Koutsouras, Dimitrios A. and Prodromakis, Themis and Malliaras, George G. and Blom, Paul W. M. and Gkoupidenis, Paschalis}, year={2019}, month={May} }
 @article{lingstedt_ghittorelli_brückner_reinholz_crăciun_torricelli_mailänder_gkoupidenis_blom_2019, title={Monitoring of Cell Layer Integrity with a Current‐Driven Organic Electrochemical Transistor}, volume={8}, ISSN={2192-2640 2192-2659}, url={http://dx.doi.org/10.1002/adhm.201900128}, DOI={10.1002/adhm.201900128}, abstractNote={Abstract}, number={16}, journal={Advanced Healthcare Materials}, publisher={Wiley}, author={Lingstedt, Leona V. and Ghittorelli, Matteo and Brückner, Maximilian and Reinholz, Jonas and Crăciun, N. Irina and Torricelli, Fabrizio and Mailänder, Volker and Gkoupidenis, Paschalis and Blom, Paul W. M.}, year={2019}, month={Jul} }
 @article{koutsouras_lingstedt_lieberth_reinholz_mailänder_blom_gkoupidenis_2019, title={Probing the Impedance of a Biological Tissue with PEDOT:PSS‐Coated Metal Electrodes: Effect of Electrode Size on Sensing Efficiency}, url={https://doi.org/10.1002/adhm.201901215}, DOI={10.1002/adhm.201901215}, abstractNote={Abstract}, journal={Advanced Healthcare Materials}, author={Koutsouras, Dimitrios A. and Lingstedt, Leona V. and Lieberth, Katharina and Reinholz, Jonas and Mailänder, Volker and Blom, Paul W. M. and Gkoupidenis, Paschalis}, year={2019}, month={Dec} }
 @article{van doremaele_gkoupidenis_van de burgt_2019, title={Towards organic neuromorphic devices for adaptive sensing and novel computing paradigms in bioelectronics}, volume={7}, ISSN={2050-7526 2050-7534}, url={http://dx.doi.org/10.1039/c9tc03247a}, DOI={10.1039/c9tc03247a}, abstractNote={We present an overview of the latest studies on organic neuromorphic and smart sensing devices and highlight the potential of these concepts to enhance the interaction efficiency between electronics and biological substances.}, number={41}, journal={Journal of Materials Chemistry C}, publisher={Royal Society of Chemistry (RSC)}, author={van Doremaele, Eveline R. W. and Gkoupidenis, Paschalis and van de Burgt, Yoeri}, year={2019}, pages={12754–12760} }
 @article{koutsouras_malliaras_gkoupidenis_2018, title={Emulating homeoplasticity phenomena with organic electrochemical devices}, volume={8}, ISSN={2159-6859 2159-6867}, url={http://dx.doi.org/10.1557/mrc.2018.53}, DOI={10.1557/mrc.2018.53}, abstractNote={Biologic neural networks are immersed in common electrolyte environment, and homeoplasticity or global factors of this environment are forcing specific normalization functions that regulate the overall network behavior. In this work, a common electrolyte is used to gate a grid of organic electrochemical devices. The electrolyte functions as a global parameter that controls collectively the device grid. Statistical analysis of the grid and the subsequent definition of global metrics reveal that the grid behaves similarly to a single device. This global control modulates the gain of the device grid, a phenomenon analog to multiplicative scaling in biologic networks. This work demonstrates the potential use of electrolytes as homeostatic media in neuromorphic device architectures.}, number={2}, journal={MRS Communications}, publisher={Springer Science and Business Media LLC}, author={Koutsouras, Dimitrios A. and Malliaras, George G. and Gkoupidenis, Paschalis}, year={2018}, month={Apr}, pages={493–497} }
 @article{rezaei‐mazinani_ivanov_proctor_gkoupidenis_bernard_malliaras_ismailova_2018, title={Monitoring Intrinsic Optical Signals in Brain Tissue with Organic Photodetectors}, volume={3}, ISSN={2365-709X 2365-709X}, url={http://dx.doi.org/10.1002/admt.201700333}, DOI={10.1002/admt.201700333}, abstractNote={Abstract}, number={5}, journal={Advanced Materials Technologies}, publisher={Wiley}, author={Rezaei‐Mazinani, Shahab and Ivanov, Anton I. and Proctor, Christopher M. and Gkoupidenis, Paschalis and Bernard, Christophe and Malliaras, George G. and Ismailova, Esma}, year={2018}, month={Feb} }
 @inproceedings{gkoupidenis_koutsouras_malliaras_2018, title={Neuromorphic devices based on organic mixed conductors}, url={http://dx.doi.org/10.1117/12.2320100}, DOI={10.1117/12.2320100}, abstractNote={Neuromorphic devices and architectures offer novel ways of data manipulation and processing, especially in data intensive applications. At a single device level, various forms of neuroplasticity have been emulated over the past years, mainly with inorganic devices. The implementation of neuroplasticity functions with these devices also enabled applications at a circuit level related to machine learning such as feature or pattern recognition. Although the field of organic-based neuromorphic devices and circuits is still at its infancy, organic materials may offer attractive features for neuromorphic engineering. Over the past years for example, a few simple neuromorphic functions have been demonstrated with biological substances and bioelectronic devices. In this work various neuromorphic devices will be presented that are based on organic mixed conductors, materials that are traditionally used in organic bioelectronics. A prominent example of a device in bioelectronics that exploits mixed conductivity phenomena is the organic electrochemical transistor (OECT). Devices based on OECTs show volatile and tunable dynamics suitable for the emulation of short-term synaptic plasticity functions. Chemical synthesis allows for the introduction of non-volatile phenomena suitable for long-term memory functions. The device operation in common electrolyte permits the definition of spatially distributed multiple inputs at a single device level. The presence of a global electrolyte in an array of devices also allows for the homeostatic or global control of the array. Global electrical oscillations can be used as global clocks that frequency-lock the local activity of individual devices in analogy to the global oscillations in the brain. Finally, “soft” interconnectivity through the electrolyte can be defined, a feature that paves the way for parallel interconnections between devices with minimal hard-wired connections.}, booktitle={Organic and Hybrid Sensors and Bioelectronics XI}, publisher={SPIE}, author={Gkoupidenis, Paschalis and Koutsouras, Dimitrios K. and Malliaras, George G.}, editor={Shinar, Ruth and Kymissis, Ioannis and Torsi, Luisa and List-Kratochvil, Emil J.Editors}, year={2018}, month={Sep} }
 @article{neuromorphic device architectures with global connectivity through electrolyte gating_2017, url={https://www.nature.com/articles/ncomms15448}, journal={Nature Communications 8,15448}, year={2017} }
 @inproceedings{gkoupidenis_koutsouras_lonjaret_rezaei-mazinani_ismailova_fairfield_malliaras_2017, title={Organic neuromorphic devices based on electrochemical concepts}, url={http://dx.doi.org/10.1117/12.2272693}, DOI={10.1117/12.2272693}, abstractNote={Neuroinspired device architectures offer the potential of higher order functionalities in information processing beyond their traditional microelectronic counterparts. In the actual neural environment, neural processing takes place in a complex and interwoven network of neurons and synapses. In addition, this network is immersed in a common electrochemical environment and global parameters such as ionic concentrations and concentrations of various hormones regulate the overall behaviour of the network. Here, various concepts of organic neuromorphic devices are presented based on organic electrochemical transistors (OECTs). Regarding the implementation of neuromorphic devices, the key properties of the OECT that resemble the neural environment are also presented. These include the operation in liquid electrolyte environment, low power consumption and the ability of formation of massive interconnections through the electrolyte continuum. Showcase examples of neuromorphic functions with OECTs are demonstrated, including short-, long-term plasticity and spatiotemporal or distributed information processing.}, booktitle={Hybrid Memory Devices and Printed Circuits 2017}, publisher={SPIE}, author={Gkoupidenis, Paschalis and Koutsouras, Dimitrios and Lonjaret, Thomas and Rezaei-Mazinani, Shahab and Ismailova, Esma and Fairfield, Jessamyn A. and Malliaras, George G.}, editor={List-Kratochvil, Emil J.Editor}, year={2017}, month={Sep} }
 @article{pedot:pss microelectrode arrays for hippocampal cell culture electrophysiological recordings_2017, url={https://www.cambridge.org/core/journals/mrs-communications/article/pedotpss-microelectrode-arrays-for-hippocampal-cell-culture-electrophysiological-recordings/B69B098DC9629881E5478FD48D07E4DB}, journal={MRS Communications, 7, 2, 259-265}, year={2017} }
 @article{kapetanakis_gkoupidenis_saltas_douvas_dimitrakis_argitis_beltsios_kennou_pandis_kyritsis_et al._2016, title={Direct Current Conductivity of Thin-Film Ionic Conductors from Analysis of Dielectric Spectroscopic Measurements in Time and Frequency Domains}, volume={120}, DOI={10.1021/acs.jpcc.6b06979}, abstractNote={A method is developed for extracting the direct current conductivity (σdc) of ion-conducting materials from frequency- and time-domain dielectric spectroscopy measurements. This method exploits the electrode polarization effects arising from the charging of an ion-blocking capacitor and provides a useful way of obtaining σdc for ionic conductors that do not exhibit a frequency- (time-) independent conductivity plateau; the latter absence of plateau is often encountered in the case of thin-film materials. It allows, by proper design of the test cells, the estimation of σdc independently of the specimen thickness, as demonstrated herein for SiO2 blocking layers and electrolyte systems made of a polyoxometalate (POM) molecule embedded in poly(methyl methacrylate) (PMMA) polymeric matrices. For different postpreparation and measurement conditions, the σdc values obtained for thick (8 μm) POM–PMMA layers are in good agreement not only with the observed conductivity plateaus but also with the values determined ...}, number={38}, journal={The Journal of Physical Chemistry C}, publisher={American Chemical Society (ACS)}, author={Kapetanakis, Eleftherios and Gkoupidenis, Paschalis and Saltas, Vassilios and Douvas, Antonios M. and Dimitrakis, Panagiotis and Argitis, Panagiotis and Beltsios, Konstantinos and Kennou, Stella and Pandis, Christos and Kyritsis, Apostolos and et al.}, year={2016}, month={Sep}, pages={21254–21262} }
 @article{gkoupidenis_koutsouras_lonjaret_fairfield_malliaras_2016, title={Orientation selectivity in a multi-gated organic electrochemical transistor}, volume={6}, DOI={10.1038/srep27007}, abstractNote={Abstract}, journal={Scientific Reports}, publisher={Springer Nature}, author={Gkoupidenis, Paschalis and Koutsouras, Dimitrios A. and Lonjaret, Thomas and Fairfield, Jessamyn A. and Malliaras, George G.}, year={2016}, month={Jun}, pages={27007} }
 @article{gkoupidenis_rezaei-mazinani_proctor_ismailova_malliaras_2016, title={Orientation selectivity with organic photodetectors and an organic electrochemical transistor}, volume={6}, DOI={10.1063/1.4967947}, abstractNote={Neuroinspired device architectures offer the potential of higher order functionalities in information processing beyond their traditional microelectronic counterparts. Here we demonstrate a neuromorphic function of orientation selectivity, which is inspired from the visual system, with a combination of organic photodetectors and a multi-gated organic electrochemical transistor based on poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS). The device platform responds preferably to different orientations of light bars, a behaviour that resembles orientation selectivity of visual cortex cells. These results pave the way for organic-based neuromorphic devices with spatially correlated functionalities and potential applications in the area of organic bioelectronics.}, number={11}, journal={AIP Advances}, publisher={AIP Publishing}, author={Gkoupidenis, Paschalis and Rezaei-Mazinani, Shahab and Proctor, Christopher M. and Ismailova, Esma and Malliaras, George G.}, year={2016}, month={Nov}, pages={111307} }
 @article{gkoupidenis_schaefer_garlan_malliaras_2015, title={Neuromorphic Functions in PEDOT:PSS Organic Electrochemical Transistors}, volume={27}, DOI={10.1002/adma.201503674}, abstractNote={UNLABELLED
Depressive short-term synaptic plasticity functions are implemented with a simple polymer poly(3,4ethylenedioxythiophene):poly(styrene sulfonate) (


PEDOT
PSS) organic electrochemical transistor device. These functions are a first step toward the realization of organic-based neuroinspired platforms with spatiotemporal information processing capabilities.}, number={44}, journal={Advanced Materials}, publisher={Wiley-Blackwell}, author={Gkoupidenis, Paschalis and Schaefer, Nathan and Garlan, Benjamin and Malliaras, George G.}, year={2015}, month={Oct}, pages={7176–7180} }
 @article{gkoupidenis_schaefer_strakosas_fairfield_malliaras_2015, title={Synaptic plasticity functions in an organic electrochemical transistor}, url={https://doi.org/10.1063/1.4938553}, DOI={10.1063/1.4938553}, abstractNote={Synaptic plasticity functions play a crucial role in the transmission of neural signals in the brain. Short-term plasticity is required for the transmission, encoding, and filtering of the neural signal, whereas long-term plasticity establishes more permanent changes in neural microcircuitry and thus underlies memory and learning. The realization of bioinspired circuits that can actually mimic signal processing in the brain demands the reproduction of both short- and long-term aspects of synaptic plasticity in a single device. Here, we demonstrate the implementation of neuromorphic functions similar to biological memory, such as short- to long-term memory transition, in non-volatile organic electrochemical transistors (OECTs). Depending on the training of the OECT, the device displays either short- or long-term plasticity, therefore, exhibiting non von Neumann characteristics with merged processing and storing functionalities. These results are a first step towards the implementation of organic-based neuromorphic circuits.}, journal={Applied Physics Letters}, author={Gkoupidenis, Paschalis and Schaefer, Nathan and Strakosas, Xenofon and Fairfield, Jessamyn A. and Malliaras, George G.}, year={2015}, month={Dec} }
 @article{koutsouras_gkoupidenis_stolz_subramanian_malliaras_martin, title={Impedance Spectroscopy of Spin-Cast and Electrochemically Deposited PEDOT:PSS Films on Microfabricated Electrodes with Various Areas}, url={http://dx.doi.org/10.1002/celc.201700297}, DOI={10.1002/celc.201700297}, abstractNote={Abstract}, journal={ChemElectroChem}, author={Koutsouras, Dimitrios A. and Gkoupidenis, Paschalis and Stolz, Clemens and Subramanian, Vivek and Malliaras, George G. and Martin, David C.}, pages={n/a-n/a} }