Swelling-Induced Stress-Assisted Transfer of Nanodiamond Arrays With a PVA Carrier Tape for Conformal Bio-Integrated Sensing and Labelling

The conformal integration of nitrogen-vacancy (NV) center nanodiamond arrays onto soft, hydrated, curvilinear biological interfaces remains a fundamental challenge for in vivo quantum sensing and imaging. Conventional transfer techniques often fail due to reliance on high temperature, corrosive chemicals, or mechanical peeling, leading to pattern damage, low fidelity, or poor biocompatibility. Here, we report a transfer strategy utilizing polyvinyl alcohol (PVA) soluble tape that enabling rapid, residue-free, high-fidelity transfer of nanodiamond patterns onto diverse biointerfaces. The success of this method is rooted in a unique “hydrate-soften-expand-self-peel” mechanism of the PVA backing. In situ mechanical tracking reveals non-uniform PVA swelling generates transient normal and shear stresses at the interface. These stresses delaminate the tape within 3 min at room temperature while promoting adhesion of nanodiamonds to the substrate. In contrast, conventional tapes undergo passive dissolution and collapse, causing residue contamination and reduced efficiency. Leveraging this mechanism, we achieve conformal patterning on ultra-soft hydrogels (∼0.6 kPa) and highly curved bio-surfaces (hair, 100 µm − 1 ). Additionally, we demonstrate a dual-identity verification system integrating data storage and physical unclonable functions on a hydrogel contact lens. This work provides a versatile tool for bio-interface engineering and a general framework for gentle, efficient transfer of functional nanomaterials.