Scalable Crackle-Lithography for Multifunctional Enclosed Plastic Nanofluidic Devices

Nanofluidic devices have attracted considerable interest from both the scientific community and industry owing to their broad potential in molecular transport, sensing, energy conversion, and information technologies. However, the widespread adoption of nanofluidic devices has been hindered by fabrication methods that rely on expensive infrastructure, sophisticated nanofabrication facilities, and labor-intensive processing. Here, we present crackle-lithography, a simple, scalable, and cost-effective approach for fabricating enclosed plastic nanofluidic devices. By harnessing spontaneous crack formation as a lithographic template, highly interconnected nanochannel networks are transferred into polyethylene terephthalate glycol (PETG) substrates through oxygen-plasma etching and subsequently sealed by thermal bonding to produce robust nanofluidic devices. The fabrication strategy is cleanroom-free, highly scalable, and compatible with high-throughput manufacturing, making it attractive for practical implementation. The resulting devices are used for studying molecular transport of gases, water, and ions, exhibit history-dependent ionic conduction with tunable memristive behavior and enable confined electroless copper deposition within the nanochannels. Their high optical transparency further allows real-time fluorescence imaging of transport processes. Together, these results establish crackle-lithography as a versatile and accessible platform for scalable nanofluidic device fabrication with potential applications in sensing, confined chemistry, neuromorphic ionics, and next-generation nanofluidic technologies.