High-throughput cell concentration using a piezoelectric pump in closed-loop viscoelastic microfluidics

Jeeyong Kim, Hyunjung Lim, Hyunseul Jee, Seunghee Choo, Minji Yang, Sungha Park, Kyounghwa Lee, Hyoungsook Park, Chaeseung Lim, Jeonghun Nam

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Cell concentration is a critical process in biological assays and clinical diagnostics for the pre-treatment of extremely rare disease-related cells. The conventional technique for sample preconcentration and centrifugation has the limitations of a batch process requiring expensive and large equipment. Therefore, a high-throughput continuous cell concentration technique needs to be developed. However, in single-pass operation, the required concentration ratio is hard to achieve. In this study, we propose a closed-loop continuous cell concentration system using a viscoelastic non-Newtonian fluid. For miniaturized and integrated systems, two piezoelectric pumps were adopted. The pumping capability generated by a piezoelectric pump in a microfluidic channel was evaluated depending on the applied voltage, frequency, sample viscosity, and channel length. The concentration performance of the device was evaluated using 13 µm particles and white blood cells (WBCs) with different channel lengths and voltages. In the closed-loop system, the focused cells collected at the center outlet were sent back to the inlet, while the buffer solution was removed to the side outlets. Finally, to expand the clinical applicability of our closed-loop system, WBCs in lysed blood samples with 70% hematocrit and prostate cancer cells in urine samples were used. Using the closed-loop system, WBCs were concentrated by ~63.4 ± 0.8-fold within 20 min to a final volume of 160 µL using 10 mL of lysed blood sample with 70% hematocrit (~3 cP). In addition, prostate cancer cells in 10 mL urine samples were concentrated by ~64.1-fold within ~11 min due to low viscosity (~1 cP).

Original languageEnglish
Article number677
Issue number6
Publication statusPublished - 2021 Jun

Bibliographical note

Funding Information:
Acknowledgments: This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A2C1014460). This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health and Welfare, Republic of Korea (grant number: HR20C0021).

Funding Information:
Funding: This research was funded by the Korean government (MSIT), grant number 2020R1A2C 1014460; and the Ministry of Health and Welfare, Republic of Korea, grant number HR20C0021.

Publisher Copyright:
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.


  • Closed-loop
  • Concentration
  • High-throughput
  • Piezoelectric pump
  • Viscoelastic fluid

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering


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