A Soft Material Flow Sensor for Micro Air Vehicles

Area of Science:

• Materials Science
• Aerospace Engineering
• Sensor Technology

Background:

• Efficient control and navigation of micro air vehicles (MAVs) require small, lightweight, durable, sensitive, fast, and low-power airspeed sensors.
• Soft materials offer advantages over traditional materials due to their ability to withstand large deformations, making them suitable for sensor design.

Purpose of the Study:

• To present a novel soft material flow sensor concept based on elastic filament velocimetry.
• To demonstrate a sensor fulfilling the criteria for micro air vehicle (MAV) applications.

Main Methods:

• The sensor measures flow velocity by relating it to the strain of a soft polydimethylsiloxane ribbon suspended between supports.
• The ribbon is made piezoresistive with silver nanowires, allowing flow velocity calibration to resistance change.
• Manufacturing utilizes common laboratory tools, avoiding cleanroom requirements, and operation uses a simple, lightweight circuit.

Main Results:

• The sensor successfully measured air flow velocities down to 4 m/s in experimental tests.
• A time-dependent analytical model indicates a sensor bandwidth of 480 Hz.
• Sensitivity and bandwidth are tunable by altering ribbon geometry and material properties.

Conclusions:

• The developed soft material flow sensor is a viable, convenient alternative for MAVs.
• The sensor's design offers tunable performance characteristics and simplified manufacturing.
• Further research is needed to address challenges like polymer creep for enhanced durability.