Biomembrane-Based Memcapacitive Reservoir Computing System for Energy-Efficient Temporal Data Processing

Reservoir computing is a highly efficient machine learning framework for processing temporal data by extracting input features and mapping them into higher dimensional spaces. Physical reservoirs have been realized using spintronic oscillators, atomic switch networks, volatile memristors, etc. However, these devices are intrinsically energy-dissipative due to their resistive nature, increasing their power consumption. Therefore, memcapacitive devices can provide a more energy-efficient approach. Herein, volatile biomembrane-based memcapacitors are leveraged as reservoirs to solve classification tasks and process time series in simulation and experimentally. This system achieves a 99.6% accuracy for spoken-digit classification and a normalized mean square error of 7.81x10-4$7.81 \times \left(10\right)<^>{- 4}$ in a second-order nonlinear regression task. Furthermore, to showcase the device's real-time temporal data processing capability, a 100% accuracy for an epilepsy detection problem is achieved. Most importantly, it is demonstrated that each memcapacitor consumes an average of 41.5 fJ of energy per spike, regardless of the selected input voltage pulse width, while maintaining an average power of 415 fW for a pulse width of 100 ms, orders of magnitude lower than those achieved by state-of-the-art devices. Lastly, it is believed that the biocompatible, soft nature of our memcapacitor renders it highly suitable for computing applications in biological environments. Reservoir computing is a highly efficient algorithm for processing temporal datasets by extracting input features and projecting them into a high-dimensional space. Biomembrane-based memcapacitors can emulate key synaptic functions due to their volatile memcapacitive property, enabling learning and computation. Herein, a biomembrane-based memcapacitive reservoir system is presented to solve classification and time-series prediction tasks, consuming only 41.5 fJ per spike.image (c) 2023 WILEY-VCH GmbH