Bio-inspired protonic memristor devices based on metal complexes with proton-coupled electron transfer

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Biological membranes utilize proton gradients for energy transduction.
• Memristors are electronic components whose resistance depends on past applied voltage.
• Proton-coupled electron transfer (PCET) is a fundamental process in biological and chemical systems.

Purpose of the Study:

• To design and fabricate a novel memristor inspired by biomembrane function.
• To investigate the use of dinuclear ruthenium complexes exhibiting PCET for memristor applications.
• To explore the role of proton gradients in electronic device operation.

Main Methods:

• Fabrication of a two-terminal device using ITO electrodes modified with dinuclear Ru complexes (RuNH-OH and RuCH-OH).
• Incorporation of a proton-conducting polymer (P4VP) between the modified electrodes.
• Characterization of the device's electrical properties under applied bias, correlating with PCET processes and pKa changes.

Main Results:

• The device exhibited switching between high and low current states at approximately ±1.10 V, driven by Ru(ii/iii) redox reactions.
• PCET processes at the electrode-polymer interfaces facilitated proton transfer, creating a proton gradient across the P4VP layer.
• The proton gradient enhanced proton conductivity, mimicking proton transport mechanisms in biological membranes.

Conclusions:

• A new class of memristors based on protonic coordination-network films with metal complexes was successfully demonstrated.
• The device mimics biomembrane functionality by utilizing proton gradients for electronic switching.
• This work opens new avenues for designing bio-inspired memristors and artificial synapses.