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Category: robotics/AI – Page 419

Refreshable memristor via dynamic allocation of ferro-ionic phase for neural reuse

This dynamic regulation capability of the device conductance creates favorable conditions for emulating synaptic plasticity. As shown in Fig. 2h, the consistent trend of device conductance evolution over 20 cycles indicates the good applicability of the ion migration working mode in emulating synaptic behavior. Furthermore, with the more elaborate design of excitation pulses for ion migration working mode, the device exhibits exceptional stability for over 120 cycles of LTP-LTD conductance changes (Supplementary Fig. 6b). Unlike stable macroscopic polarization, when the external electric field is smaller than the built-in electric field resulting from the ion migration, migrated Cu+ ions tend to spontaneously return to the origin lattice, leading the conductance to relax to its initial state22. As shown in Fig. 2i, a series of pulses was initially applied to induce Cu+ ion migration for varying low-resistance states of the device. Subsequently, a series of pulses with a period of 1.5 s, where 0 V is applied for 1.4 s and −0.6 V is applied for 0.1 s, were used to detect the evolution trend of the device conductance. As anticipated, the influence of migrated ions on the barrier noticeably decayed when no bias voltage was applied and eventually disappeared after 45 seconds. Notably, the effect of interface defects on the volatile state can be considered negligible (Supplementary Fig. 11).

Thus far, selective control of the device’s working mode has been achieved through precise pulse engineering. Short, high-amplitude pulses predominantly influence ferroelectric polarization, while longer, lower-amplitude pulses primarily drive ion migration. Beyond differences in on/off ratio and retention capabilities, the opposite shifts in the transfer curves provide further experimental evidence distinguishing them (Supplementary Fig. 12). In addition, the tunability of dual memristive mechanisms has also been verified in devices with varying CIPS thicknesses, as shown in Supplementary Fig. 13. The above results indicate that our device can work adaptably under the ferroelectric polarization and ion migration mode, respectively. And those memristive mechanisms with different retention characteristics all exhibit good applicability in emulating LTP-LTD characteristics. Overall, our device shows enormous promising potential in integrating neural reuse with memristor-based neural networks.

A refreshable memristor should possess two key properties: refresh and restoration. To confirm the refresh capability of the device, Fig. 3a illustrates the emulation of synaptic potentiation and depression behaviors achieved by cyclically configuring the device to ion migration mode, after every two induced ferroelectric polarizations. Across at least 4 cycles of the redeployment, the device exhibits consistent conductance changes in its respective working modes and well-defined independence between different working modes. This suggests that the motion extent of ferroionic can be precisely regulated solely by adjusting the amplitude and period of the excitation pulse, enabling the realization of both volatile and non-volatile working modes within a single device. Crucially, the experimental results demonstrate that redeployment does not compromise the performance in any given working mode of the device.

Chemical research often contains inaccurate mass measurement data, according to AI analysis

AI-powered data analysis tools have the potential to significantly improve the quality of scientific publications. A new study by Professor Mathias Christmann, a chemistry professor at Freie Universität Berlin, has uncovered shortcomings in chemical publications.

Using a Python script developed with the help of modern AI language models, Christmann analyzed more than 3,000 published in Organic Letters over the past two years. The analysis revealed that only 40% of the chemical research papers contained error-free mass measurements. The AI-based data analysis tool used for this purpose could be created without any prior programming knowledge.

“The results demonstrate how powerful AI-powered tools can be in everyday research. They not only make complex analyses accessible but also improve the reliability of scientific data,” explains Christmann.

AI simulates 500 million years of evolution to discover artificial fluorescent protein

Gould’s thesis has sparked widespread debate ever since, with some advocating for determinism and others supporting contingency. In his 1952 short story A Sound of Thunder, science fiction author Ray Bradbury recounted how a time traveler’s simple act of stepping on a butterfly in the age of the dinosaurs changed the course of the future. Gould made a similar point: “Alter any early event, ever so slightly and without apparent importance at the time, and evolution cascades into a radically different channel.”

Scientists have been exploring this problem through experiments designed to recreate evolution in the lab or in nature, or by comparing species that have emerged under similar conditions. Today, a new avenue has opened up: AI. In New York, a group of former researchers from Meta — the parent company of social networks Facebook, Instagram, and WhatsApp — founded EvolutionaryScale, an AI startup focused on biology. The EvolutionaryScale Model 3 (ESM3) system created by the company is a generative language model — the same kind of platform that powers ChatGPT. However, while ChatGPT generates text, ESM3 generates proteins, the fundamental building blocks of life.

ESM3 feeds on sequence, structure, and function data from existing proteins to learn the biological language of these molecules and create new ones. Its creators have trained it with 771 billion data packets derived from 3.15 billion sequences, 236 million structures, and 539 million functional traits. This adds up to more than one trillion teraflops (a measure of computational performance) — the most computing power ever used in biology, according to the company.

Google’s Titans Give AI Human-Like Memory

On a broader level, by pushing AI toward more human-like processing, Titans could mean AI that thinks more deeply than humans — challenging our understanding of human uniqueness and our role in an AI-augmented world.

At the heart of Titans’ design is a concerted effort to more closely emulate the functioning of the human brain. While previous models like Transformers introduced the concept of attention—allowing AI to focus on specific, relevant information—Titans takes this several steps further. The new architecture incorporates analogs to human cognitive processes, including short-term memory, long-term memory, and even the ability to “forget” less relevant information. Perhaps most intriguingly, Titans introduces a concept that’s surprisingly human: the ability to prioritize surprising or unexpected information. This mimics the human tendency to more easily remember events that violate our expectations, a feature that could lead to more nuanced and context-aware AI systems.

The key technical innovation in Titans is the introduction of a neural long-term memory module. This component learns to memorize historical context and works in tandem with the attention mechanisms that have become standard in modern AI models. The result is a system that can effectively utilize both immediate context (akin to short-term memory) and broader historical information (long-term memory) when processing data or generating responses.

Brain-controlled interface experiment provides empirical support for one-way neural activity paths

Neural network models that are able to make decisions or store memories have long captured scientists’ imaginations. In these models, a hallmark of the computation being performed by the network is the presence of stereotyped sequences of activity, akin to one-way paths. This idea was pioneered by John Hopfield, who was notably co-awarded the 2024 Nobel Prize in Physics. Whether one-way activity paths are used in the brain, however, has been unknown.

A collaborative team of researchers from Carnegie Mellon University and the University of Pittsburgh designed a clever experiment to perform a causal test of this question using a (BCI). Their findings provide empirical support of one-way activity paths in the brain and the computational principles long hypothesized by neural network models.

Stereotyped sequences of neural population activity, also known as , is believed to underlie numerous brain functions, including , sensory perception, decision making, timing, and memory, among others. The group focused on the brain’s motor system for their work, recently published in Nature Neuroscience, where neural population activity can be used to control a BCI.

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