Harnessing Stochastic Collisions for Deterministic Dry Assembly via Viscoelastic Microtraps

Controlled dry assembly of functional granules is limited by rebound, stochastic occupancy, and the difficulty of combining impact-tolerant capture with clean release. Here, we report a materials-interface principle that converts random collisions into deterministic capture by programming a viscoelastic adhesive state via partial photopolymer conversion. Cure-state-controlled viscoelasticity suppresses rebound through a tunable threshold momentum ( p 50 ) while shifting the adhesion mode from area-spanning conformal contact to localized, off-center binding. A geometric scale factor S enables single occupancy at S = 0.2, with 0.18% defects across 1104 traps and linear scalability from 4 to 100 sites. The platform supports detachment without detectable residue, stable reuse, and discrete granule manipulation yielding a quantitative PCR C t -load correlation of R 2 = 0.991. These results establish deterministic dry assembly through materials-level programming, without field-based actuation or precise contact alignment, for dry manufacturing and quantitative solid-state handling.