On‐Demand Cargo Release via Low‐Voltage Actuated Flexible Microchamber Arrays

We design, fabricate, and characterize novel electrically triggered mu -chamber arrays, demonstrating their suitability for precise, localized cargo release. Using biocompatible materials, scalable hot-embossing, and gold nanoparticle functionalization, our devices operate at low actuation voltages, ideal for safe biomedical applications, including implantable drug delivery. Real-time fluorescence imaging with Nile Red staining visualizes sealing film dynamics during opening, confirming electrical stimulation and localized Joule heating. We analyze the polymeric film's structural evolution, revealing a "curtain-like" opening mechanism driven by film softening and increased vapor pressure, leading to dewetting at bio-compatible temperatures. Experimental observations are confirmed through continuum-scale modeling of the opening process, using a square root retraction law that predicts a dynamic response on the order of a few seconds. Devices use polyimide (Kapton) substrates patterned with 30 mu m-deep square mu -chambers (50 x 50 mu m2), equipped with titanium pads and gold nanoparticles to reduce actuation voltage to 1 V. Sealing uses a thermolabile polycaprolactone (PCL) film, enabling on-demand cargo release. We assess sealing efficiency, loading capacity, and release performance via SEM, fluorescence microscopy, and UV-vis spectrophotometry using fluorescent model drugs. While designed for implantable drug delivery, the system's adaptable design and scalable fabrication support broader applications, including regenerative medicine, smart prosthetics, environmental monitoring, and peptide electronics.