Periodic Reporting for period 3 - MITICS (Mixed Ionic and electronic Transport In Conjugated polymers for bioelectronicS)
Berichtszeitraum: 2023-08-01 bis 2025-07-31
Brain computer interfaces (BCIs) is a modern technology that aims to improve quality of life and longevity, addressing the widespread effects of aging populations, including the growth of mental illness and neurological disorders, for example sclerosis, stroke, brain/spinal cord injury, muscular dystrophy. Therefore, BCIs represent a much promising technology for restoring function loss and are used for rehabilitation and entertainment/gaming.
However, the potential of BCIs is strongly hampered by the invasiveness vs. performance trade-off.
MITICS is developing a highly sensitive and biocompatible amplifying transducer platform for less invasive BCIs. We will leverage the Organic Electrochemical Transistor (OECT), a transducer that was recently shown to yield superior recordings of brain activity than electrodes, and dramatically improve its performance through the design of bespoke materials and coupling with high-gain, low-power amplifiers to achieve a paradigm shift in the invasiveness of BCIs. These highly sensitive amplifying transducers will be fabricated using printing processes which should allow custom designs and a strong decrease in fabrication costs. This breakthrough will allow BCIs to increase decoding accuracy and adoption, thus getting this technology out of the current blocking situation and to the general population and patients at scale
However, the potential of BCIs is strongly hampered by the invasiveness vs. performance trade-off.
MITICS is developing a highly sensitive and biocompatible amplifying transducer platform for less invasive BCIs. We will leverage the Organic Electrochemical Transistor (OECT), a transducer that was recently shown to yield superior recordings of brain activity than electrodes, and dramatically improve its performance through the design of bespoke materials and coupling with high-gain, low-power amplifiers to achieve a paradigm shift in the invasiveness of BCIs. These highly sensitive amplifying transducers will be fabricated using printing processes which should allow custom designs and a strong decrease in fabrication costs. This breakthrough will allow BCIs to increase decoding accuracy and adoption, thus getting this technology out of the current blocking situation and to the general population and patients at scale
The project has advanced the field of organic electrochemical transistors (OECTs) and organic mixed ionic–electronic conductors (OMIECs) by combining synthesis, characterization, modelling, device engineering and application development. New synthetic routes were established to produce defect-free conjugated polymers, significantly improving OECT performance and providing benchmark materials for the consortium. A wide range of small-molecule and polymeric OMIECs were developed, including ion-selective small-molecule systems and conjugated microporous polymers with tunable architectures. Complementary to the synthetic efforts, multiscale modelling revealed detailed mechanisms of ion-charge interactions in thin-films and guided molecular design strategies towards chemical structures and morphologies yielding the optimal balance between hydrophilic and hydrophobic interactions and maximizing the product µC*, while advanced spectroscopic and structural methods deepened the understanding of electronic and ionic transport.
These material insights enabled innovative device concepts. Blending strategies were introduced to overcome the scarcity of ambipolar OMIECs, achieving multifunctional devices with superior capacitance, mobility, and operational flexibility. Improvements in printing and manufacturing platforms allowed the transition from depletion-mode to accumulation-mode OECTs, enabling low-power complementary circuits. Novel OECT-based circuits were further integrated into conformable systems for bioelectronic applications. Parallel work established validation pipelines, extending the potential impact of OECTs to brain–computer interfaces and EEG monitoring.
Overall, the project has provided a rational framework for OMIEC design, advanced the technological maturity of OECTs, and demonstrated their relevance for sensing, signal processing, and neurotechnology. Dissemination has been extensive, through high-impact publications, conference presentations, and patent application, ensuring strong visibility and paving the way for future exploitation
These material insights enabled innovative device concepts. Blending strategies were introduced to overcome the scarcity of ambipolar OMIECs, achieving multifunctional devices with superior capacitance, mobility, and operational flexibility. Improvements in printing and manufacturing platforms allowed the transition from depletion-mode to accumulation-mode OECTs, enabling low-power complementary circuits. Novel OECT-based circuits were further integrated into conformable systems for bioelectronic applications. Parallel work established validation pipelines, extending the potential impact of OECTs to brain–computer interfaces and EEG monitoring.
Overall, the project has provided a rational framework for OMIEC design, advanced the technological maturity of OECTs, and demonstrated their relevance for sensing, signal processing, and neurotechnology. Dissemination has been extensive, through high-impact publications, conference presentations, and patent application, ensuring strong visibility and paving the way for future exploitation
Record-breaking OECT performance has been achieved with a novel homocoupling-free conjugated polymer, enabling the fabrication of the first all-printed, vertically stacked accumulation-mode devices through combined screen and inkjet printing. These were processed with a biodegradable solvent, yielding reproducible and stable p-type OECTs with excellent performance. Alongside this, new OMIEC materials introduced unprecedented control of mixed ionic–electronic conduction, including the first demonstration of potassium–sodium selectivity and electropolymerized conjugated microporous polymers with tunable ionic channels. Advanced in-operando spectroscopy, spanning visible to terahertz frequencies, provided unique insights into electronic–ionic interplay in OECTs, with covalent organic frameworks highlighting how porosity and backbone order can be balanced for optimized transport. A computational framework integrating atomistic simulations with device models was also established, opening pathways for both OECT and neuromorphic material design. On the device side, complementary all-printed circuits marked a major milestone, offering scalable, sustainable, and low-cost solutions for flexible and wearable electronics, with impact potential in diagnostics, textiles, and healthcare. The demonstration of adaptive organic circuits enabling on-device logic further set the stage for soft, low-power neurotechnology.