Single neuromorphic memristor closely emulates multiple synaptic mechanisms for energy efficient neural networks by Christoph Weilenmann, Alexandros Nikolaos Ziogas, Till Zellweger, Kevin Portner, Marko Mladenović, Manasa Kaniselvan, Timoleon Moraitis, Mathieu Luisier, Alexandros Emboras ISBN 10.1038/S41467-024-51093-3 instant download

Single neuromorphic memristor closely emulates multiple synaptic mechanisms for energy efficient neural networks by Christoph Weilenmann, Alexandros Nikolaos Ziogas, Till Zellweger, Kevin Portner, Marko Mladenović, Manasa Kaniselvan, Timoleon Moraitis, Mathieu Luisier, Alexandros Emboras ISBN 10.1038/S41467-024-51093-3 instant download

Biological neural networks do not only include long-term memory and weightmultiplication capabilities, as commonly assumed in artificial neural networks, but also more complex functions such as short-term memory, short-termplasticity, and meta-plasticity - all collocated within each synapse. Here, we demonstrate memristive nano-devices based on SrTiO₃ that inherently emulate all these synaptic functions. These memristors operate in a non-filamentary, low conductance regime, which enables stable and energy efficient operation. They can act as multi-functional hardware synapses in a class of bio-inspired deep neural networks (DNN) that make use of both long- and short-term synaptic dynamics and are capable of meta-learning or learning-to-learn. The resulting bio-inspired DNN is then trained to play the video game Atari Pong, a complex reinforcement learning task in a dynamic environment. Our analysis shows that the energy consumption of the DNN with multi-functionalmemristive synapses decreases by about two orders of magnitude as compared to a pure GPU implementation. Based on this finding, we infer that memristive devices with a better emulation of the synaptic functionalities do not only broaden the applicability of neuromorphic computing, but could also improve the performance and energy costs of certain artificial intelligence applications.