Piezoresistive Carbon Nanofiber-Based Cilia-Inspired Flow Sensor

Area of Science:

• MEMS technology
• Biomimetics
• Nanotechnology

Background:

• Biological cilia offer high-resolution, sensitive flow sensing.
• Existing artificial cilia sensors face fabrication challenges and high costs.
• Need for cost-effective, sensitive artificial flow sensors persists.

Purpose of the Study:

• To develop a novel, inexpensive fabrication process for cilia-inspired artificial flow sensors.
• To create a highly sensitive artificial cilia flow sensor using a unique material combination.
• To demonstrate the sensor's potential in various microfluidic and biomedical applications.

Main Methods:

• Fabrication of artificial cilia using a novel process flow.
• Integration of high-aspect-ratio titanium pillars on electrospun carbon nanofiber (CNF) membranes.
• Calibration of tip displacement and flow sensing performance (steady-state and oscillatory).

Main Results:

• Achieved a lower detection threshold of 50 µm for tip displacement.
• Demonstrated steady-state airflow sensitivity of 6.16 mV/(m s^-1).
• Recorded oscillatory flow sensitivity of 26 mV/(m s^-1) with a detection limit of 12.1 mm/s.

Conclusions:

• The proposed method enables inexpensive and sensitive artificial cilia flow sensor fabrication.
• Carbon nanofibers (CNFs) show promise as novel sensing elements in MEMS and flexible sensors.
• The developed sensors are suitable for precise flow monitoring in microfluidics and biomedical devices.