Periodic Reporting for period 1 - BioResORGEL (Bioresorbable Organic Electronic Devices)
Periodo di rendicontazione: 2021-08-20 al 2023-08-19
Conventional electronics, including consumers products and medical devices, mostly rely on metal-oxide semiconductors such as silicon, germanium, etc., which are difficult and expensive to dispose of. As electronics become increasingly integrated in of our daily lives, there is a growing demand for technologies that decompose after a period of stable operation without leaving a permanent mark. For consumers electronics, such as smart packaging, solutions that are based on organic and resorbable materials are set to contribute towards the sustainability target to reduce waste and promote the manufacture of greener products. In the biomedical field, bioresorbable devices prospect to advance temporary implants, such as bioelectronic interfaces for peripheral nerve regeneration after injury (affecting over 730´000 people/year in the EU), where device resorption has the advantage to make risky secondary surgical procedures for device retrieval unnecessary.
The aim of the BioResOrgel project was to develop materials and devices that provide stable operation as required for applications and that completely resorb in the body after service life. Bioresorbable materials have the potential to provide a new stream of electronic devices that completely degrade after having completed their function, thereby advancing applications, such as temporary medical implants and consumers electronics. The research was carried out at the Kungliga Tekniska Högskolan (KTH) under the supervision of Professor Anna Herland.
The aim of the BioResOrgel project was to develop materials and devices that provide stable operation as required for applications and that completely resorb in the body after service life. Bioresorbable materials have the potential to provide a new stream of electronic devices that completely degrade after having completed their function, thereby advancing applications, such as temporary medical implants and consumers electronics. The research was carried out at the Kungliga Tekniska Högskolan (KTH) under the supervision of Professor Anna Herland.
Part of the project was devoted to the development of new conjugated polymers (macromolecules capable con conduct both electronic and ionic charge carriers) with suitable properties for application in bioelectronic devices. Current synthesis strategies rely on toxic monomers and chlorinated solvents. We found that aldol polymerization, using toluene as a solvent and no toxic precursors, can be used as a strategy for the synthesis of conjugated polymers with mixed ionic/electronic conductivity needed for device operation. This synthesis method is “greener” with respect to conventional polymerizations generally used in the field, as it is free from metal catalysts and organotin precursors. I assessed the performance of these materials as core component in a class of amplifying devices called electrochemical transistors, showing that these conjugated polymers are indeed not only greener but also suitable core device components.
Another research direction arising from materials considerations focused on improving device performance and stability while minimizing the amount of conjugated polymer, thereby providing cheaper materials without compromising device performance. I found that diluting certain types of organic semiconductors with a host-insulating polymer increases device overall current and stability upon repeated ON/OFF cycles. The new materials open up vast opportunities towards low-cost bioelectronics.
In collaboration with the group of A. F. Wistrand and T. Fuoco, I have developed and characterized films made of poly(trimethylene carbonate). Project results have shown that the material can be used to generate crosslinked thin films that are insoluble in water, yet can be degraded by the action of enzymes such as lipase and esterase. These materials are promising alternatives to replace non-degradable substrates in electronic devices.
I furthermore delved into critical issues for the microfabrication of bioelectronic devices. Current device microfabrication strategies rely on photolithography. These processes are time consuming and challenging to implement for the realization of bioresorbable electronics, where materials are generally prone to decompose in harsh conditions (e.g. organic solvents, high temperatures, etc.). We have implemented a new process for the cleanroom-free patterning of organic electronic devices. This process, relying on direct laser writing, has been validated for the patterning of biosensors and amplifying circuits. I foresee that such method will solve critical issues in the fast prototyping of bioelectronics devices.
The research conducted within the BioResOrgel project has been presented at a number of national and international conferences. Two peer-reviewed journal articles have already been published. A patent and two manuscripts have been submitted. I moreover participated to a number of outreach activities to disseminate project results. Such activities will continue past the project end date, as a new patent application is under development.
Another research direction arising from materials considerations focused on improving device performance and stability while minimizing the amount of conjugated polymer, thereby providing cheaper materials without compromising device performance. I found that diluting certain types of organic semiconductors with a host-insulating polymer increases device overall current and stability upon repeated ON/OFF cycles. The new materials open up vast opportunities towards low-cost bioelectronics.
In collaboration with the group of A. F. Wistrand and T. Fuoco, I have developed and characterized films made of poly(trimethylene carbonate). Project results have shown that the material can be used to generate crosslinked thin films that are insoluble in water, yet can be degraded by the action of enzymes such as lipase and esterase. These materials are promising alternatives to replace non-degradable substrates in electronic devices.
I furthermore delved into critical issues for the microfabrication of bioelectronic devices. Current device microfabrication strategies rely on photolithography. These processes are time consuming and challenging to implement for the realization of bioresorbable electronics, where materials are generally prone to decompose in harsh conditions (e.g. organic solvents, high temperatures, etc.). We have implemented a new process for the cleanroom-free patterning of organic electronic devices. This process, relying on direct laser writing, has been validated for the patterning of biosensors and amplifying circuits. I foresee that such method will solve critical issues in the fast prototyping of bioelectronics devices.
The research conducted within the BioResOrgel project has been presented at a number of national and international conferences. Two peer-reviewed journal articles have already been published. A patent and two manuscripts have been submitted. I moreover participated to a number of outreach activities to disseminate project results. Such activities will continue past the project end date, as a new patent application is under development.
The materials developed during the time of this project have the potential to increase the sustainability of bioelectronic devices: from benign solvents to degradable device components. This is a significant progress with respect to standard materials, relying on toxic tin-containing monomers and chlorinated solvents for the synthesis. The fabrication strategies developed here are expected to have a wide impact in phasing out photolithography for the microfabrication of organic bioelectronic devices.