Microfluidic chip design to advance detection and analysis of circulating tumor cells

Early in tumor development, circulating tumor cells (CTCs) detach from primary or metastatic lesions and are important biomarkers for diagnosis and treatment response. But they are rare in blood circulating through the body and difficult to isolate without compromising cell viability. Current technologies, such as dielectrophoresis (DEP), which exerts force on dielectric particles, are effective but show low throughput and are insufficient at revealing their geometric design parameter interactions.

Wang et al. designed an experiment to optimize key geometric parameters of an electrode DEP chip.

“When CTCs and blood cells flow through a microchannel with specially arranged electrodes, an electric field ‘pushes’ them toward channel walls, leaving normal blood cells mostly unaffected,” said author Xiangyang Zu. “The key is that the electric field won’t harm the cells.”

The researchers combined computer simulations with response surface methodology — a statistical technique — to optimize three parameters: electrode angle, electrode spacing, and channel height. By analyzing their interactions, they produced a design that significantly increases throughput while maintaining electric field safety.

“Previously, changing one parameter at a time was like trying to tune a piano with only one key,” said author Yipei Wang. “Using response surface methodology, we finally saw how all the geometric factors play together. And the best part? Our chip doesn’t hurt the cells, so doctors can study them afterward.”

The optimized chip represents a major step toward practical liquid biopsy.

“We have broken the longstanding throughput bottleneck with DEP microfluidics,” said Zu. “This is not just an incremental improvement. This opens the door to real-time, label-free CTC detection that could one day be as routine as a complete blood count.”

Source: “Design and numerical simulation of a high-throughput dielectrophoresis microfluidic chip for continuous capture of active circulating tumor cells,” by Yipei Wang, Zhigang Hu, Cuisi Ou, Jinye Li, and Xiangyang Zu, AIP Advances (2026). The article can be accessed at https://doi.org/10.1063/5.0311481 .