CMOS Capacitive Sensing in Life Science Applications

Since its inception within the microelectronics industry, CMOS capacitive sensing has emerged as a transformative approach for label-free, noninvasive interrogation of biological systems. By exploiting the dielectric variations introduced by cells, biomolecules or microdroplets in proximity to patterned electrode structures, CMOS platforms transduce these changes into electrical signals with high sensitivity and throughput. Advances in circuit design—such as charge-based capacitance measurement, ring-oscillator frequency shifts and current-mode readouts—have expanded the dynamic range from attofarad to femtofarad scales, enabling real-time monitoring of cell proliferation, viability and morphological dynamics. Integration with microfluidics and on-chip data processing has yielded compact lab-on-CMOS systems capable of multiplexed analysis for applications ranging from cancer biomarker screening to tissue-engineering studies. Ongoing improvements in resolution, power consumption and packaging now allow continuous operation in harsh biological media, highlighting the global promise of CMOS capacitive sensing in life science research and point-of-care diagnostics.

Research from Nature Portfolio

A recent study demonstrated the power of CMOS capacitive matrices for single-cell characterisation and tracking. Employing a ring-oscillator-based pixel readout circuit within a dense sensor array, researchers distinguished hepatocellular carcinoma from normal liver cells by mapping subtle capacitance differences across the chip surface. A bespoke algorithm reconstructed cell position and morphology in real time, achieving femtofarad-level sensitivity and revealing the potential of integrated CMOS platforms for label-free, high-throughput cellular analysis.

CMOS Capacitive Sensing in Life Science Applications publication trend

The graph below shows the total number of articles in cmos capacitive sensing in life science applications across all publications each year (not limited to Nature Index journals).

Technical terms

Complementary Metal–Oxide–Semiconductor (CMOS): A technology for fabricating integrated circuits by combining p-type and n-type transistors to achieve low power consumption and high device density.

Capacitance: The ability of a system to store electric charge, which changes in response to variations in dielectric properties near sensor electrodes.

Ring oscillator: A circuit of odd-numbered inverters connected in a loop, whose oscillation frequency shifts in response to changes in load capacitance.

Lab-on-CMOS: An integrated platform that merges microfluidic handling and sensing elements directly onto a CMOS chip for compact, automated biological assays.

Interdigitated electrodes: Comb-like electrode structures with alternating fingers that enhance the interaction between the sensing surface and the target analyte.

References

1. Measuring and modeling macrophage proliferation in a lab-on-CMOS capacitance sensing microsystem. Frontiers in Bioengineering and Biotechnology (2023).
2. A Biosensor-CMOS Platform and Integrated Readout Circuit in 0.18-μm CMOS Technology for Cancer Biomarker Detection. Sensors (2017).
3. Toward High Throughput Core-CBCM CMOS Capacitive Sensors for Life Science Applications: A Novel Current-Mode for High Dynamic Range Circuitry. Sensors (2018).
4. Low temperature co-fired ceramic packaging of CMOS capacitive sensor chip towards cell viability monitoring. Beilstein Journal of Nanotechnology (2016).
5. LTCC Packaged Ring Oscillator Based Sensor for Evaluation of Cell Proliferation. Sensors (2018).
6. CMOS based capacitive sensor matrix for characterizing and tracking of biological cells. Scientific Reports (2022).
7. Oral Cells-On-Chip: Design, Modeling and Experimental Results. Bioengineering (2022).
8. A Multidisciplinary Approach toward CMOS Capacitive Sensor Array for Droplet Analysis. Micromachines (2024).
9. An Automatic Offset Calibration Method for Differential Charge-Based Capacitance Measurement. Journal of Low Power Electronics and Applications (2021).