The development, published today (June 11) in Nature^[1], represents a major leap toward the realization of thinner, faster and more energy-efficient electronics, the researchers said. They created a complementary metal-oxide semiconductor (CMOS) computer — technology at the heart of nearly every modern electronic device — without relying on silicon. Instead, they used two different 2D materials to develop both types of transistors needed to control the electric current flow in CMOS computers: molybdenum disulfide for n-type transistors and tungsten diselenide for p-type transistors.

“Silicon has driven remarkable advances in electronics for decades by enabling continuous miniaturization of field-effect transistors (FETs),” said Saptarshi Das^[2], the Ackley Professor of Engineering and professor of engineering science and mechanics at Penn State, who led the research. FETs control current flow using an electric field, which is produced when a voltage is applied. “However, as silicon devices shrink, their performance begins to degrade. Two-dimensional materials, by contrast, maintain their exceptional electronic properties at atomic thickness, offering a promising path forward.”

Das explained that CMOS technology requires both n-type and p-type semiconductors working together to achieve high performance at low power consumption — a key challenge that has stymied efforts to move beyond silicon. Although previous studies demonstrated small circuits based on 2D materials, scaling to complex, functional computers had remained elusive, Das said.

“That’s the key advancement of our work,” Das said. “We have demonstrated, for the first time, a CMOS computer built entirely from 2D materials, combining large area grown molybdenum disulfide and tungsten diselenide transistors.”

The team used metal-organic chemical vapor deposition (MOCVD) — a fabrication process that involves vaporizing ingredients, forcing a chemical reaction and depositing the products onto a substrate — to grow large sheets of molybdenum disulfide and tungsten diselenide and fabricate over 1,000 of each type of transistor. By carefully tuning the device fabrication and post-processing steps, they were able to adjust the threshold voltages of both n- and p-type transistors, enabling the construction of fully functional CMOS logic circuits.

“Our 2D CMOS computer operates at low-supply voltages with minimal power consumption and can perform simple logic operations at frequencies up to 25 kilohertz,” said first author Subir Ghosh, a doctoral student pursuing a degree in engineering science and mechanics under Das’s mentorship.

Ghosh noted that the operating frequency is low compared to conventional silicon CMOS circuits, but their computer — known as a one instruction set computer — can still perform simple logic operations.

“We also developed a computational model, calibrated using experimental data and incorporating variations between devices, to project the performance of our 2D CMOS computer and benchmark it against state-of-the-art silicon technology,” Ghosh said. “Although there remains scope for further optimization, this work marks a significant milestone in harnessing 2D materials to advance the field of electronics.”

Das agreed, explaining that more work is needed to further develop the 2D CMOS computer approach for broad use, but also emphasizing that the field is moving quickly when compared to the development of silicon technology.

“Silicon technology has been under development for about 80 years, but research into 2D materials is relatively recent, only really arising around 2010,” Das said. “We expect that the development of 2D material computers is going to be a gradual process, too, but this is a leap forward compared to the trajectory of silicon.”

Ghosh and Das credited the 2D Crystal Consortium Materials Innovation Platform^[3] (2DCC-MIP) at Penn State with providing the facilities and tools needed to demonstrate their approach. Das is also affiliated with the Materials Research Institute^[4], the 2DCC-MIP and the Departments of Electrical Engineering and of Materials Science and Engineering, all at Penn State. Other contributors from the Penn State Department of Engineering Science and Mechanics include graduate students Yikai Zheng, Najam U. Sakib, Harikrishnan Ravichandran, Yongwen Sun, Andrew L. Pannone, Muhtasim Ul Karim Sadaf and Samriddha Ray; and Yang Yang, assistant professor. Yang is also affiliated with the Materials Research Institute and the Ken and Mary Alice Lindquist Department of Nuclear Engineering at Penn State. Joan Redwing, director of the 2DCC-MIP and distinguished professor of materials science and engineering and of electrical engineering, and Chen Chen, assistant research professor, also co-authored the paper. Other contributors include Musaib Rafiq and Subham Sahay, Indian Institute of Technology; and Mrinmoy Goswami, Jadavpur University.

The U.S. National Science Foundation, the Army Research Office and the Office of Naval Research supported this work in part.

The research, led by Gaurav Sahay of Oregon State University's College of Pharmacy, was conducted in collaboration with Oregon Health & Science University and the University of Helsinki. Findings were published in a pair of papers, in Nature Communications and the Journal of the American Chemical Society.

Scientists created and tested more than 150 different materials and discovered a new type of nanoparticle that can safely and effectively carry messenger RNA and gene-editing tools to lung cells. In studies with mice, the treatment slowed the growth of lung cancer and helped improve lung function that had been limited by cystic fibrosis, a condition caused by one faulty gene.

Researchers also developed a chemical strategy to build a broad library of lung-targeting lipids used in the nanocarriers. These materials form the foundation for the new drug delivery system and could be customized to reach different organs in the body, Sahay said.

"The streamlined synthesis method makes it easier to design future therapies for a wide range of diseases," he said. "These results demonstrate the power of targeted delivery for genetic medicines. We were able to both activate the immune system to fight cancer and restore function in a genetic lung disease, without harmful side effects."

Oregon State's K. Yu Vlasova, D.K. Sahel, Namratha Turuvekere Vittala Murthy, Milan Gautam and Antony Jozic were co-authors of the Nature Communications paper, which also included scientists from OHSU and the University of Helsinki. OSU's Murthy, Jonas Renner, Milan Gautam, Emily Bodi and Antony Jozic teamed with Sahay on the other study.

"Our long-term goal is to create safer, more effective treatments by delivering the right genetic tools to the right place," said Sahay. "This is a major step in that direction."

These studies were funded by the Cystic Fibrosis Foundation, the National Cancer Institute and the National Heart, Lung and Blood Institute.

Do larger male elk have proportionally larger antlers? The answer is no. In fact, larger individuals tend to have disproportionately larger antlers -- a phenomenon known as positive allometry. This pattern, where certain body parts grow disproportionately large relative to body size, is observed not only in mammals but also in animals such as beetles and fiddler crabs. Evolutionary biologists interpret such traits as evidence of sexual selection -- a process in which physical features evolve because they offer an advantage in competing for mates.

Male earwigs are known to show positive allometry in their forceps -- pincer-like appendages at the tip of the abdomen -- which are believed to have evolved as weapons in battles with rivals. But what about females? Female earwigs also have forceps -- so what purpose do they serve?

Tomoki Matsuzawa (then an undergraduate) and Associate Professor Junji Konuma from Toho University's Department of Biology conducted the first quantitative study of female earwig forceps. Using morphometric analysis on the maritime earwigs Anisolabis maritima, they found that female forceps also display positive allometry -- suggesting that they, too, may have evolved through sexual selection.

The team measured the head, thorax, abdomen, and bilateral forceps dimensions and analyzed shape differences in both sexes. They found that males have thick, short, and curved forceps, while females have thin, long, and straight ones -- indicating clear sexual dimorphism. When they plotted body size against forceps width and length on a log-log scale, the results revealed a pattern of positive allometry in males: forceps width increased disproportionately with body size. Surprisingly, positive allometry was also found in females -- in the length of the forceps. These results suggest that while the sexes differ in forceps shape, both may have evolved them as weapons -- albeit in different ways.

Associate Professor Konuma explains:"A previous behavioral study has shown that female earwigs compete for small, non-aggressive males. Our findings suggest that female forceps may have evolved as effective weapons in such competition. While most earlier research focused only on males, our study highlights the importance of considering female traits as well when studying the evolution of insect morphologies."

These findings were published on June 12, 2025, in the Biological Journal of the Linnean Society.