An acoustofluidic-enhanced molecular diagnostic platform

As molecular diagnostics are increasingly applied to personalized disease management and infectious disease control, tools that originally only exist in laboratories are now being moved closer to patients in order to achieve point-of-care testing (POCT). Ideally, POCT should be both robust and user-friendly, but conflicting requirements in macroscopic fluid handling and fast microscopic mixing create a trade-off that limits scalability.

Various active mixing technologies were developed to solve this tradeoff. Acoustofluidic platforms, for example, leverage acoustic streaming effects for fluid transfer. Shi et al. further refined this strategy by introducing a mechanical component into its design.

“Many acoustofluidic devices are standalone mixing units needing manual sample transfer, while passive-mixing microfluidic chips suffer slow reaction rates,” said author Tiechuan Li. “We wanted to build a fully automated, enclosed POCT platform that solves mixing, fluid control, and contamination risks together for decentralized molecular diagnostics.”

To this end, the team developed an acoustofluidic-enhanced integrated system (AEIS) that enables division of labor between fluid transfer and mixing. A programmable rotary valve conducts multi-channel fluid selection and displacement, while a GHz bulk acoustic wave resonator promotes active mixing within one single reaction chamber, enabling the separate optimization of both macroscopic and microscopic components of the AEIS device.

In validation tests, the AEIS detected mutations of the gene EGFR at its limit of detection within 30 minutes, highlighting its potential for sensitive, efficient, and contamination-free POCT.

“Our work demonstrates how to combine high-energy acoustofluidics with precision mechanical automation and delivers a validated engineering blueprint for next-generation integrated POCT nucleic-acid instruments,” said Li.

Source: “Acousto-mechanofluidic synergy: A GHz-resonator-enhanced rotary valve system for fully automated, efficient point-of-care nucleic acid testing,” by Hongtao Shi, Zhiwei Li, Bingnan Wang, Xuexin Duan, and Tiechuan Li, Nanotechnology and Precision Engineering (2026). The article can be accessed at https://doi.org/10.1063/5.0337475 .