DNA, the fundamental blueprint of life, holds an astonishing capacity for information storage, with a single gram theoretically capable of holding approximately 215 million gigabytes of data. Harnessing this immense density within electronic devices promises a future of dramatically more efficient data centers, accelerated processing speeds, and systems equipped to manage ever-increasing data complexity. The primary hurdle has been the incompatibility between biological DNA and electronic materials, a challenge that Penn State researchers have now ingeniously overcome with a novel approach, detailed in a recent publication in Advanced Functional Materials and the subject of a patent application. Their breakthrough lies in the synergistic combination of two key components: custom-designed synthetic DNA and crystalline perovskite, a semiconductor already recognized for its utility in solar cells, lasers, and data storage.

"Biology and electronics are different domains," explains Kavya S. Keremane, a co-corresponding author and postdoctoral researcher in materials science and engineering at Penn State. "Bridging these two fields required developing an entirely new materials platform that allows them to function seamlessly together. By combining the information storage capabilities of DNA with the exceptional electronic properties of perovskite semiconductors, we created a bio-hybrid system that fundamentally changes how low-power memory devices can be designed." This innovative bio-hybrid system represents a paradigm shift in the design of low-power memory devices.

The research team has successfully engineered a memory resistor, or "memristor," that operates with remarkable energy efficiency. Unlike conventional resistors, which maintain a fixed resistance and lose their stored information when power is cut, memristors possess the unique ability to retain a record of past electrical activity. They can "remember" the direction of electrical current flow even after the power source is disconnected. This capability allows for both information storage and processing within the same physical location, mimicking the highly parallel and efficient functioning of neurons in the human brain. Such an architecture is crucial for supporting more simultaneous and sophisticated data processing tasks. While traditional electronic memory systems face limitations in storage capacity and power consumption, especially as the demand for artificial intelligence (AI) escalates, DNA’s unparalleled ability to pack vast amounts of information into a minuscule space with minimal energy consumption offers a compelling solution.

"As the demand for artificial intelligence (AI) grows, we need a new strategy for low-power, high-storage devices," emphasizes Bed Poudel, a co-corresponding author and research professor of materials science and engineering at Penn State. He further elaborates that AI and other cutting-edge technologies are increasingly leaning towards neuromorphic computing, a field focused on creating systems that emulate the human brain’s architecture and functionality. These brain-inspired systems are designed to process multiple inputs concurrently, making decisions informed by past experiences and future projections. Poudel highlights a critical advantage: "Usually, it takes more power to store more information. Our device, however, consumes 100 times less power and the storage capacity is higher than traditional storage devices, like flash drives."

The construction of this groundbreaking device involved a meticulous process of integrating custom-designed synthetic DNA sequences with thin films of perovskite. Specifically, silver nanoparticles were introduced to a layer of these specially engineered DNA sequences. This technique, known as "doping," involves introducing a small quantity of a different material to impart specific properties. In this instance, the addition of silver nanoparticles served a dual purpose: it enabled the DNA to conduct electricity and facilitated a more ordered arrangement of its molecular units.

Synthetic DNA presented several advantages over its naturally occurring counterpart. Natural DNA, characterized by long, intertwined strands, can be difficult to manipulate precisely. In contrast, the short, rigid pieces of synthetic DNA can be arranged with exceptional accuracy at the nanoscale. Neela H. Yennawar, a research professor and director of the Penn State Huck Institutes of the Life Sciences’ Biomolecular Interactions Core Facility and co-author, underscores this point: "We can computationally determine exactly which sequences we need and how long they should be, and then we can rationally design them with synthetic DNA. These structures can be systematically doped with silver and other ions and engineered to interface seamlessly with perovskites—transforming DNA from a biological macromolecule into a programmable, multifunctional nanomaterials platform." This molecular engineering allows for precise control over structural organization, tunable electrical conductivity, and functional capabilities that are unattainable with natural DNA in thin film applications.

The synergistic interplay between the silver-doped DNA and perovskite is where the true innovation lies. Together, they form bio-hybrid pathways that efficiently guide the flow of electrical current through the device. The researchers observed reliable electron movement at voltage levels below 0.1 volt, a remarkably low threshold compared to the 120 volts of standard U.S. outlets. Furthermore, the device demonstrated predictable responses when the direction of the current was reversed. The meticulously designed DNA structures, in conjunction with the perovskite, also imparted exceptional stability to the device. It maintained consistent operation at temperatures approaching 250 degrees Fahrenheit and remained functional at room temperature for over six weeks, significantly surpassing the performance benchmarks of existing perovskite-based memory storage devices.

Crucially, the new system can perform the same memory functions as comparable technologies while consuming a mere one-tenth of the power. This extraordinary efficiency makes the approach particularly appealing for future electronics designed to handle massive data volumes with substantially reduced energy footprints. "Using just the DNA or just perovskite alone did not produce near as robust a result as the combination," Keremane affirms. "It’s this combination that enables a very high memory storage density that requires very little power."

Looking ahead, the research team is committed to further refining this technology and exploring broader applications for bio-inspired electronic systems. "Nature has the solution—we just have to find it and apply it," Poudel concludes. "This work of integrating DNA into electronics to do amazing things gives a glimpse into what is possible."

The research team also includes co-corresponding author Luyao Zheng, postdoctoral researcher in materials science and engineering; Haodong Wu, doctoral student in materials science and engineering; Jiamao Zheng, former master’s student in materials science and engineering; Shashank Priya, former professor of materials science and engineering; Chiranth C. Ravi, former master’s student in the Huck Institutes of the Life Sciences; Abhinav Gorthy and co-corresponding author Rashmi Jha from the University of Minnesota. Funding for this pioneering research was provided by the U.S. National Science Foundation, the National Institutes of Health, Penn State, and the University of Minnesota.