Three recent studies present distinct paths for expanding the concept of semiconductors beyond traditional structures: circuits made from bacterial colonies that can perform logic operations, a device based on antiferromagnetic materials that retains recent inputs and forgets older ones, and a high-entropy oxide material that combines semiconducting properties with very low thermal conductivity. These findings were published in separate studies and reviewed by Semiconductor Engineering on August 25, 2026.
Bacteria Perform Logic Operations
Researchers at the Massachusetts Institute of Technology (MIT) engineered Pantoea agglomerans bacteria to function as transistors in circuits designed for environmental monitoring. The team designed two types of transistors: one is turned on by the molecule OC-6, while the other is turned off in the presence of the same molecule. In both cases, the transistor detects a target molecule, OC-12, and then produces an output molecule called OHC-14.
The researchers used three bacterial strains to translate the OHC-14 signal into an output that could be passed to another transistor. The bacterial colonies were printed on agar-containing plates, with a distance of approximately 5 millimeters between colonies so that signals could travel to the nearest colony and then to the next in one direction.
The experiments demonstrated the implementation of multi-input, OR, and implication logic gates. The transistors were also combined to build circuits for adding two signals, processing multiple signals, and demultiplexing. The largest circuit contained 24 bacterial colonies. However, each computation takes approximately eight hours, a duration the researchers considered suitable for biological applications, but not for replacing conventional computers. The team hopes to use these circuits on plant leaves or roots to monitor and respond to environmental stresses.
Forgetting as a Computational Function
In South Korea, researchers from Seoul National University and Sungkyunkwan University developed a semiconductor device based on an antiferromagnetic material that can retain recent inputs and automatically forget older information. The two-terminal device combines zirconium dioxide with amorphous indium gallium zinc oxide (a-IGZO).
Improving the composition of a-IGZO produced clear differences in current even with limited changes in the device state, achieving an on-to-off ratio of approximately 890. It also distinguished 16 different combinations of 4-bit inputs and achieved 90.4% accuracy in recognizing handwritten digits while reducing input data by 75%.
What changes in practice? Instead of treating the material’s return to its original state after the voltage is removed as a defect, the researchers used it as a “forgetting” mechanism serving time-series data processing. The team says the device combines nonlinear transformation, short-term memory, and natural initialization in a single component, but it still plans to reduce the device’s footprint and verify the circuits at the array level before expanding it into an edge artificial intelligence system for audio, biological, and environmental signals.
Mixing Multiple Elements to Create a New Material
Researchers at Carnegie Mellon University and Pennsylvania State University transformed an insulating metal oxide into a semiconductor using high-entropy mixing. The A6WO4 material is based on incorporating manganese, iron, cobalt, nickel, copper, and zinc into a tungsten oxide framework in a single crystal structure known as wolframite.
The material combines semiconducting transport with extremely low thermal conductivity, two properties that are usually difficult to combine in oxides, according to the researchers. The significance of the result lies in the fact that chemical disorder was not used randomly, but as a means of tuning electronic and thermal properties together. The team believes this could open the way to thermoelectric device materials that convert waste heat into electricity, although this application remains within the realm of research possibilities requiring further development.