Toward Scalable Conformal Electrochemical Imprinting: Mechanical Perspective

Optical metasurfaces for hyperspectral imaging, advanced optics, and co-packaged optoelectronic interconnects demand innovative patterning techniques for transparent materials in the near-infrared spectrum with sub-100 nm resolution and three-dimensional geometrical control. Metal-assisted chemical imprinting (Mac-Imprint) combines imprint contact mechanics with metal-assisted chemical etching to micromachine free-form 3D architectures in single-crystalline inorganic semiconductors. Integration of Mac-Imprint into existing commercial nanoimprinting systems and its process scale-up have been hindered due to the lack of compliant stamp technologies that are compatible with the pneumatic actuation and system-level contact control. Here, an Au-coated porous polyvinylidene fluoride (PVDF) membrane on a polyimide (PI) backing is integrated into a pneumatically actuated Mac-Imprint cell to enable uniform conformal contact on both planar and curved silicon substrates. A system-level finite-element model is developed to capture laminate mechanics and interfacial contact with the substrate. The model is validated by (i) measuring maximum transverse deflection of a freestanding laminate using a displacement sensor and (ii) mapping induced biaxial strain upon contact using digital image correlation; simulations reproduce measured deflection and strain fields within ∼4% without fitting parameters. The validated model is then used to quantify pressure-induced in-plane stretch that governs pattern, identify stress concentrations, pressure distribution, and establish a safe operating window against laminate yielding and loss of transfer fidelity. The resulting framework supports scalable cell design, mechanics-based inverse stamp pre-compensation, and conformal electrochemical patterning of nonplanar substrates such as lenses.