Periodic Reporting for period 1 - ICONIC (In-situ & operando organiC electrochemical transistors monitored by non-destructive spectroscopies for Organic cmos-like NeuromorphIc Circuits)
Periodo di rendicontazione: 2024-05-01 al 2025-04-30
Imagine a future where healthcare is ultimately smart! Imagine altruistic technology that humans do not feel and which saves good health and well-being in the world! Imagine the unthinkable: such intelligent technology will prevent, even highly unpredictable, brain disorders as epileptic crisis! That is the ICONIC’s purpose. By this project, we envision the future of smart healthcare where an autonomous closed-loop feedback system, invisible and painless, prevent or cure chronic diseases. Human-being would have no longer to worry about the rigor of medication treatment or overmedication side-effects ? For this, we envision to realize a truly conformable and ultraflexible organic electronics-based artificial intelligence which could be skin-worn or implantable in an human body. An example of where this development could operate a paradigm shift is applications using Brain-Machine Interfaces (BMIs). Promising studies demonstrate the usefulness of BMIs for neurological pathologies such as i) stroke rehabilitation, ii) communication of people with disabilities, iii) recovery from chronic diseases and mental and cognitive disorders. One of the most common neurological conditions (estimated prevalence of 0.5%–1%) is epilepsy. Even though many drugs have been developed, 30% of these patients remain drug-resistant. This therapeutic gap can be reduced with local drug delivery. To stop the genesis and propagation of seizures, the right dose of the right drug needs to be distributed at the right time. The most sophisticated technique that can provide this feature is iontronic technology. To predict a seizure onset, the early indicators need to be identified and recognized. This is a challenge that can be overcome by a trained neuromorphic circuit. The combination of these two technologies will make it possible to demonstrate the closed-loop system envisaged at the end of the project, as a first proof of concept in a laboratory setting, a stepping stone towards a better life for these patients.
Current available electronics which is interfacing with living entities (i.e. the ”bioelectronics“) is poorly adapted to the inherent functioning of the human body and makes it intrusive in its use: Silicon electronics is rigid and operates by electronic currents flow. Oppositely, the human body is soft, communicates and is activated by ionic flow. This inherent incompatibility requires new solutions. Polymer electronics could remove such a barrier. Indeed, (semi)conducting polymers as active layers and its substrates are ultra-thin, therefore soft, biocompatible, reusable, conformable. Such (semi)conducting, more particularly here, Polymeric Mixed Ion-to-Electron Conductors (PMIECs) have recently emerged as a promising platform to transport both ions and charges (electrons, holes) allowing a direct interfacing of electronics with living entities. For instance, it has been shown that PMIEC electrodes give a better signal-to-noise ratio, tackling thus the lifetime barrier to use BMIs in clinical studies. Nonetheless, there are no truly conformable and biocompatible electronic circuits capable of making in-situ autonomous and intelligent decisions without compromising the beneficial “bio” properties of those PMIECs. Flexible inorganic electronics provides computing capabilities, but no truly direct transducing properties as PMIECs-based sensors do. Moreover, thinned-silicon wafers become flexible, but remain fragile and very brittle, not conducive to the use at the direct interface with ”the living world”. Organic ElectroChemical Transistors (OECTs)-based circuits connected to PMIECs-based sensors would make a truly monolithic homogeneous integrated system, ideally matching sensing/signal processing properties. The pathway towards ICONIC’s vision requires unprecedented developments in “brain-inspired” (or neuromorphics) OECT-based analog electronics. Such analog electronic circuits are based on i) transistors that operate in accumulation mode and ii) a Complementary-Metal-Oxide-Semiconductor (CMOS) architecture (i.e. association of N-type and P-type) for low power consumption.
Current available electronics which is interfacing with living entities (i.e. the ”bioelectronics“) is poorly adapted to the inherent functioning of the human body and makes it intrusive in its use: Silicon electronics is rigid and operates by electronic currents flow. Oppositely, the human body is soft, communicates and is activated by ionic flow. This inherent incompatibility requires new solutions. Polymer electronics could remove such a barrier. Indeed, (semi)conducting polymers as active layers and its substrates are ultra-thin, therefore soft, biocompatible, reusable, conformable. Such (semi)conducting, more particularly here, Polymeric Mixed Ion-to-Electron Conductors (PMIECs) have recently emerged as a promising platform to transport both ions and charges (electrons, holes) allowing a direct interfacing of electronics with living entities. For instance, it has been shown that PMIEC electrodes give a better signal-to-noise ratio, tackling thus the lifetime barrier to use BMIs in clinical studies. Nonetheless, there are no truly conformable and biocompatible electronic circuits capable of making in-situ autonomous and intelligent decisions without compromising the beneficial “bio” properties of those PMIECs. Flexible inorganic electronics provides computing capabilities, but no truly direct transducing properties as PMIECs-based sensors do. Moreover, thinned-silicon wafers become flexible, but remain fragile and very brittle, not conducive to the use at the direct interface with ”the living world”. Organic ElectroChemical Transistors (OECTs)-based circuits connected to PMIECs-based sensors would make a truly monolithic homogeneous integrated system, ideally matching sensing/signal processing properties. The pathway towards ICONIC’s vision requires unprecedented developments in “brain-inspired” (or neuromorphics) OECT-based analog electronics. Such analog electronic circuits are based on i) transistors that operate in accumulation mode and ii) a Complementary-Metal-Oxide-Semiconductor (CMOS) architecture (i.e. association of N-type and P-type) for low power consumption.
ICONIC uses innovative in situ operando non-destructive analytical and spectroscopic methods to investigate with an unprecedented accuracy ion-to-electron transduction in OECT from the molecular up to the micrometric scale. This provides the key knowledge needed to make a technological leap in the development of organic flexible devices. Four ambitious specific objectives are defined:
- SO1: Realize (macro)molecular engineering of P- and N-type PMIECs
- SO2: Establish structure versus property relationships of PMIECs
- SO3: Unify the description of the OECT’s physical mechanisms
- SO4: Achieve Organic Neuromorphics Sensor
In the first reporting period (Month 12) and focusing on SO1, we used a small-molecule approach to mixed ionic-electronic conductors. We have successfully prepared five naphthalene diimide based small-molecule materials, which is the first step in identifying how molecular design can be used, providing greater control in optimizing both parameters rather than finding the best compromise. Initial characterization of these materials points to significant differences, which we are now working to fully understand across the consortium so that we can establish clear structure-property relations and utilize this knowledge to design second and third generations of materials with improved properties.
In the first reporting period (Month 12) and focusing on SO2, we have agreed on a common preparation protocol to ensure the use of identical processing parameters. Information of requirements and benefits of the different experimental techniques have been discussed and shared between partners to make exchange decisions more transparent between all project partners from PIs to Postdocs, PhDs and students independent of their time of joining the project.
In the first reporting period (Month 12) and focusing on SO3, by optimizing the bulk doping process, we have successfully reduced contact resistance as low as 1 ohm.cm and improved the transconductance performance of both p-type and n-type OECTs. The cutoff frequency results do not show a saturation effect as we shrink the channel length: it indicates us the possibility to go below 1 µm channel length without deteriorating the performances of such accumulation-mode OECTs. Nonetheless, despite a reduction in channel length by a factor of 10, there is no dramatic improvement of the electronic switching time, remaining largely below the time the OECT turns ON (i.e around 5 ms) indicating that the ionic switching time has a dominant influence.
In the first reporting period (Month 12) and focusing on SO4, we developed SPICE models and have show good agreements with the measured transfer characteristics of both p-type and n-type OECTs.
- SO1: Realize (macro)molecular engineering of P- and N-type PMIECs
- SO2: Establish structure versus property relationships of PMIECs
- SO3: Unify the description of the OECT’s physical mechanisms
- SO4: Achieve Organic Neuromorphics Sensor
In the first reporting period (Month 12) and focusing on SO1, we used a small-molecule approach to mixed ionic-electronic conductors. We have successfully prepared five naphthalene diimide based small-molecule materials, which is the first step in identifying how molecular design can be used, providing greater control in optimizing both parameters rather than finding the best compromise. Initial characterization of these materials points to significant differences, which we are now working to fully understand across the consortium so that we can establish clear structure-property relations and utilize this knowledge to design second and third generations of materials with improved properties.
In the first reporting period (Month 12) and focusing on SO2, we have agreed on a common preparation protocol to ensure the use of identical processing parameters. Information of requirements and benefits of the different experimental techniques have been discussed and shared between partners to make exchange decisions more transparent between all project partners from PIs to Postdocs, PhDs and students independent of their time of joining the project.
In the first reporting period (Month 12) and focusing on SO3, by optimizing the bulk doping process, we have successfully reduced contact resistance as low as 1 ohm.cm and improved the transconductance performance of both p-type and n-type OECTs. The cutoff frequency results do not show a saturation effect as we shrink the channel length: it indicates us the possibility to go below 1 µm channel length without deteriorating the performances of such accumulation-mode OECTs. Nonetheless, despite a reduction in channel length by a factor of 10, there is no dramatic improvement of the electronic switching time, remaining largely below the time the OECT turns ON (i.e around 5 ms) indicating that the ionic switching time has a dominant influence.
In the first reporting period (Month 12) and focusing on SO4, we developed SPICE models and have show good agreements with the measured transfer characteristics of both p-type and n-type OECTs.
At this stage of the project's progress (Month 12), it is not possible to draw any conclusions from the results obtained to date.