An integrated optofluidic platform enabling label-free single-cell sorting and culture

Abstract

Optical tweezers (OT) technology enables high-precision single-cell manipulation but is fundamentally constrained by the trade-off between hydrodynamic drag and trapping stability; overcoming fluidic forces often requires elevated laser power that compromises cell viability. Here, we present an integrated optical tweezers and microwell array (MA-chip) platform (OTMA) that decouples optical trapping from fluidic transport via a Z-axis “lift-and-drift” retrieval strategy. By using microwells as hydrodynamic shelters, the platform enables deterministic single-cell sorting and automated collection into standard 96-well plates for subsequent culture while minimizing shear-induced perturbations. The system exhibits robust performance for targets ≥3 µm, demonstrating broad applicability from microorganisms to large mammalian tumor cells. Furthermore, it achieves deterministic sorting with near-complete recovery at a throughput of 20–30 cells min⁻¹, requiring <1 s of laser exposure per cell. Importantly, the platform exhibits excellent biocompatibility, maintaining >90% viability in fragile mammalian cells and achieving a clonal expansion rate of 93.8% in yeast. By shifting the design priority from maximal throughput to functional cell quality, OTMA shows strong potential as a robust, label-free tool for applications requiring high-fidelity cellular states, such as rare-cell cloning and stress-sensitive single-cell omics.