AlaaDdin Al-Shidaifat

In designing neuromorphic circuits and systems, developing compact and energy-efficient neuron and synapse circuits is essential for high-performance on-chip neural architectures. Toward that end, this work utilizes the advanced low-power and compact 7nm FinFET technology to design leaky integrate-and-fire (LIF) neuron and spike-timing-dependent plasticity (STDP) circuits. In the proposed STDP circuit, only six FinFETs and three small capacitors (two 10fF and 20fF) have been utilized to realize STDP learning. Moreover, 12 transistors and two capacitors (20fF) have been employed for designing the LIF neuron circuit. The evaluation results demonstrate that besides 60% area saving, the proposed STDP circuit achieves 68% improvement in total average power consumption and 43% lower energy dissipation compared to previous works. The proposed LIF neuron circuit demonstrates 34% area saving, 46% power, and 40% energy saving compared to its counterparts. The neuron can also tune the firing frequency within 5MHz-330MHz using an external control voltage. These results emphasize the potential of the proposed neuron and STDP learning circuits for compact and energy-efficient neuromorphic computing systems.

Memristive devices have garnered significant attention in the field of electronics over the past few decades. The reason behind this immense interest lies in the ubiquitous nature of memristive dynamics within nanoscale devices, offering the potential for revolutionary applications. These applications span from energy-efficient memories to the development of physical neural networks and neuromorphic computing platforms. In this research article, the angle toppling technique (ATT) was employed to fabricate titanium dioxide (TiO₂) nanoparticles with an estimated size of around 10 nm. The nanoparticles were deposited onto a 50 nm SiO_x thin film (TF), which was situated on an n-type Si substrate. Subsequently, the samples underwent annealing processes at temperatures of 550 °C and 950 °C. The structural studies of the sample were done by field emission gun-scanning electron microscope (FEG-SEM) (JEOL, JSM-7600F). The as-fabricated sample exhibited noticeable clusters of nanoparticles, which were less prominent in the samples annealed at 550 °C and 950 °C. The element composition revealed the presence of titanium (Ti), oxygen (O₂), and silicon (Si) from the substrate within the samples. X-ray diffraction (XRD) analysis revealed that the as-fabricated sample predominantly consisted of the rutile phase. The comparative studies of charge storage and endurance measurements of as-deposited, 550 °C, and 950 °C annealed devices were carried out, where as-grown device showed promising responses towards brain computing applications. Furthermore, the teaching–learning-based optimization (TLBO) technique was used to conduct further comparisons of results.

After professor Chua has coined Memristor (non-volatile) device, numerous research on Memristor were accomplished. Memristor is two terminal inherent memory devices, capable of working in parallel computing (storage and computation). Its conductance may be modulated by applying electrical input through the oxygen vacancies. It is also capable of mimicking the behavior of brain cell. In fact, artificial intelligence has opened new avenues in both academic and industrial fields. In these research findings, we have focus, to study the morphological and electrical characteristics of 1 x 1 Hafnium dioxides (HfO2) memristors crossbar array for developing Artificial Vision System.

The brain’s learning and adaptation processes heavily rely on the concept of associative memory. One of the most basic associative learning processes is classical conditioning. This work presents a memristive neural network-based associative memory system. The system can emulate Pavlovian conditioning principles including acquisition, extension, generalization, differentiation, and spontaneous recovery that have not been considered in most of the previous counterparts. The proposed circuit can emulate these principles thanks to the resistance-changing characteristics of the memristor. Generalization has been achieved by providing both unconditional and neutral stimuli to the network to reduce the memristance of the memristor. Differentiation has been attained by employing unconditional and conditional stimuli in a training scheme to obtain a certain memristance that causes the network to respond differently to both stimuli. A revival of an exterminated stimuli is also done by increasing the synaptic weight of the system. Compared to previous designs, the proposed memristive circuit can implement all the functions of conditional reflex. Our rigorous simulations demonstrated that the proposed memristive system can condition neutral stimuli, show generalization between similar stimuli, distinguish dissimilarities between the generalized stimuli, and recover faded stimuli.