Periodic Reporting for period 2 - PRINGLE (Protein-based next generation electronics)
Berichtszeitraum: 2023-05-01 bis 2024-10-31
PRiNGLE builds on the very recent discovery in biology of what are called cable bacteria that can transmit high electrical currents over centimeter long distances. The marine bacteria produce self-assembling, long, high conductivity proteins (HCP) of exceptional electronic properties not previously seen in biological materials. Based on these microbially-derived HCP fibers, a novel class of exclusively protein-based electronic materials, PROTEONICS, with suitable conductive, semi-conductive and insulating properties for electronics, can be initiated. These materials will have radically different properties (biocompatibility, biodegradability, biofunctionalization) than materials currently used in electronics. PRiNGLE aims to unlock the technological potential of this unique material, thus kickstarting PROTEONICS into a new innovative electronic technology. To demonstrate this, we will construct - for the first time - an electronic circuit that is exclusively protein-based. For this, PRiNGLE aims to realize a challenging science-towards-technology breakthrough: we need to take the conductive fibers “out of the natural bacteria” and turn them into an electronic base material. To this end, we need to demonstrate that (i) we can produce HCP fibers under controlled in vitro conditions, (ii) keep their electronic functionality, and (iii) show that they can be patterned and processed into electronic components.
PRiNGLE will provide the fundamental and technological basis for PROTEONICS by addressing the following objectives: (1) achieving HCP fiber self-assembly under controlled in vitro conditions, thus allowing scalable recombinant production of conductive protein fibers in “microbial factories”, (2) by demonstrating that HCP fibers form a performant electronic base material, ensuring that electronic properties remain stable under relevant application conditions (e.g. atmospheric stability of conduction), (3) by developing fabrication and patterning technologies to produce electronic components from HCP fibers, and (4) by showing that the electronic properties of HCP can be tuned in a fit-for-purpose manner through genetic engineering, thus obtaining a new class of electronic materials with functionality that is hitherto unavailable. As proof-of-concept, we will (5) develop the first ever PROTEONICS circuit in which all electronic components are protein-based (wires, inductors, resistors, insulators, capacitors, transistors). This way, PRiNGLE will provide a convincing proof-of-concept for a fully biobased, CO2-neutral electronic technology where custom-crafted protein structures act as elementary active and passive components in a new generation of biocompatible and biodegradable electronic devices.
To reach the PRiNGLE objectives, we need to address a challenging technological development at the interface of biology and electronics. The project combines unique and highly interdisciplinary research in biology (microbiology, structural biology), chemistry (protein biochemistry, electrochemistry), physics (electronic properties, quantum char.ge transport models) and engineering (organic electronics, electronic component development and characterization). Tight integration between these disciplines is clear from the combination of experimental approaches with theory development and modelling, the range of scales studied (from single molecules to macroscale components), and the integration of fundamental, applied and translational research.
PRiNGLE will provide the fundamental and technological basis for PROTEONICS by addressing the following objectives: (1) achieving HCP fiber self-assembly under controlled in vitro conditions, thus allowing scalable recombinant production of conductive protein fibers in “microbial factories”, (2) by demonstrating that HCP fibers form a performant electronic base material, ensuring that electronic properties remain stable under relevant application conditions (e.g. atmospheric stability of conduction), (3) by developing fabrication and patterning technologies to produce electronic components from HCP fibers, and (4) by showing that the electronic properties of HCP can be tuned in a fit-for-purpose manner through genetic engineering, thus obtaining a new class of electronic materials with functionality that is hitherto unavailable. As proof-of-concept, we will (5) develop the first ever PROTEONICS circuit in which all electronic components are protein-based (wires, inductors, resistors, insulators, capacitors, transistors). This way, PRiNGLE will provide a convincing proof-of-concept for a fully biobased, CO2-neutral electronic technology where custom-crafted protein structures act as elementary active and passive components in a new generation of biocompatible and biodegradable electronic devices.
To reach the PRiNGLE objectives, we need to address a challenging technological development at the interface of biology and electronics. The project combines unique and highly interdisciplinary research in biology (microbiology, structural biology), chemistry (protein biochemistry, electrochemistry), physics (electronic properties, quantum char.ge transport models) and engineering (organic electronics, electronic component development and characterization). Tight integration between these disciplines is clear from the combination of experimental approaches with theory development and modelling, the range of scales studied (from single molecules to macroscale components), and the integration of fundamental, applied and translational research.
PRiNGLE members have gained significant knowledge on electrical properties, conduction mechanism, and the conductive structure in cable bacteria. The model of the conductive structure and conduction mechanism has been finetuned/updated in a number of aspects:
(i) The periplasmic fibers consist of a bundle of polymerized metallo-proteins. The molecular structure of the Ni/S-cofactor (a nickel bis(1,2-dithiolene) (NiBiD) complex cofactor) is determined.
(ii) Density functional theory model analysis shows that a simple, linear arrangement of NiBiD cofactors cannot explain the high conductivities recorded.
(iii) Experimental measurement of the conductivity over small (< 50 nm) distances and down to cryogenic temperatures shows novel features (Coulomb blockade, negative resistances), which suggest a limited numbers of conduction channels within the fibers (fewer than anticipated).
(iv) The hypothesis that the fibers consist of a loose bundle of fibrils does not hold.
(v) Ni/S-cofactor oligomers are stacked along a one-dimensional metal organic framework that extends along the axis of the fibrils, thereby providing one-dimensional “highways” for efficient long-distance electron transport.
(i) The periplasmic fibers consist of a bundle of polymerized metallo-proteins. The molecular structure of the Ni/S-cofactor (a nickel bis(1,2-dithiolene) (NiBiD) complex cofactor) is determined.
(ii) Density functional theory model analysis shows that a simple, linear arrangement of NiBiD cofactors cannot explain the high conductivities recorded.
(iii) Experimental measurement of the conductivity over small (< 50 nm) distances and down to cryogenic temperatures shows novel features (Coulomb blockade, negative resistances), which suggest a limited numbers of conduction channels within the fibers (fewer than anticipated).
(iv) The hypothesis that the fibers consist of a loose bundle of fibrils does not hold.
(v) Ni/S-cofactor oligomers are stacked along a one-dimensional metal organic framework that extends along the axis of the fibrils, thereby providing one-dimensional “highways” for efficient long-distance electron transport.
The main results archived during the first 30 months of the project:
(i) The biochemistry of the conductive structures in cable bacteria is totally different compared to known biological systems.
(ii) The biophysics of the conduction mechanism in cable bacteria appears profoundly different compared to other biological systems.
(iii) The conductive system in cable bacteria shows an extremely metal-lean form of organic conductivity, thus providing a novel design principle for bio-inspired electronic materials.
In the next 18 months the consortium will particularly focus the research activities on following three research questions:
(i) What is the secret of high conductivity in cable bacteria? What is the molecular structure providing high conduction? What is the mechanism of conduction?
(ii) Can this mechanism be mimicked in an engineered way to make bio-based materials that can be integrated as electronic components? Can we make HCP fibers in vitro?
(iii) What is the technological application potential? What could be “killer applications”?
(i) The biochemistry of the conductive structures in cable bacteria is totally different compared to known biological systems.
(ii) The biophysics of the conduction mechanism in cable bacteria appears profoundly different compared to other biological systems.
(iii) The conductive system in cable bacteria shows an extremely metal-lean form of organic conductivity, thus providing a novel design principle for bio-inspired electronic materials.
In the next 18 months the consortium will particularly focus the research activities on following three research questions:
(i) What is the secret of high conductivity in cable bacteria? What is the molecular structure providing high conduction? What is the mechanism of conduction?
(ii) Can this mechanism be mimicked in an engineered way to make bio-based materials that can be integrated as electronic components? Can we make HCP fibers in vitro?
(iii) What is the technological application potential? What could be “killer applications”?