Researchers may have found a way to bring nanoscale sensor production out of specialized cleanrooms and into standard semiconductor fabs. In a paper published in Science Advances, a team from KTH Royal Institute of Technology describes a new fabrication method for nanopores the tiny holes in ultra-thin membranes that lie at the heart of many sensing and diagnostic technologies. The researchers compare their approach to yanking a tree stump out of the ground with a rope.
Nanopores are essential in medical research and increasingly in clinical settings, powering sequencing tools used for disease outbreak tracking, cancer genomics, and pathogen identification. Their usefulness comes from their minuscule openings in extremely thin materials, which allow individual molecules like DNA or proteins to be detected and studied one at a time. The catch is that making these pores has traditionally meant carving them individually with slow, costly, hard-to-scale techniques such as electron-beam drilling or TEM (Transmission Electron Microscope) sculpting, with most sensor chips relying on just one nanopore per membrane.
Frank Niklaus, a professor of micro and nanosystems at KTH, explains that the new method instead relies on mechanical stress engineered directly into the material to generate the holes. According to Xinxin Liu, a KTH doctoral student and the study's lead author, the process starts with layered materials deposited on a silicon wafer: a top layer is pre-stressed and held under tension, beneath it sits a sacrificial layer that gets etched away except for a small, precisely shaped anchor point, and below that lies the actual sensor membrane, where the nanopore will eventually form. As the sacrificial layer is etched away, the tensioned top layer — anchored only at that one small point eventually rips a nanoscale piece out of the membrane below it, punching through and creating the pore.
"It's similar to pulling a stump from the ground with a rope," Liu explains. "The tensioned beam acts like the rope, latching onto the anchor point and tearing it free from the membrane, which plays the role of the ground holding the stump."
Because the process relies on fracture mechanics rather than pore-by-pore drilling, it can produce entire arrays of nanopores simultaneously as small as roughly 6–10 nanometers rather than one at a time. The team tested the technique successfully across multiple membrane materials, including dielectric, metallic, and semiconductor types, and showed that the resulting nanopores worked effectively for DNA analysis and molecule detection. Liu notes that the group has already patented the technique and launched a startup to push it toward commercial use, adding that samples have already been shipped to a collaborator for testing, meaning the work has moved beyond the lab stage.
