Multi-parameter controlled acoustofluidic assembly of colloidal and cellular structures

Acoustic patterning provides a non-contact and label-free strategy for organizing colloidal scale particles and living cells while preserving biological activity, showing strong potential for biofabrication and engineered microtissue construction. However, a comprehensive understanding of how acoustic parameters, device architecture and sample properties collectively influence the patterning outcomes remains limited. In this work, a controllable acoustic patterning platform was established to investigate particle organization driven by standing surface acoustic waves (SSAWs). The study systematically examines how acoustic frequency, input power, channel height and the pattern window affect particle aggregation time and three-dimensional spatial distributions. The results reveal clear regulatory mechanisms that enable precise and reproducible control of the acoustic patterning behavior. In addition, temperature monitoring further defines a safe operating range, ensuring optimal biocompatibility. Building on this mechanistic understanding, an open-type acoustic tweezer system was developed to achieve rapid and orderly patterning of myoblasts (C2C12) and fibroblasts (NIH/3T3) within a hydrogel matrix under optimized acoustic conditions. Compared with untreated controls, acoustically patterned cells exhibited enhanced alignment and upregulated expression of myogenic genes. This study provides a quantitative parameter mapping and practical design framework for acoustic assembly of particle and cell systems at the colloidal scale, supporting reproducible interface guided biofabrication.