Development of acoustic & airflow sensors inspired by the hair sensilla of insects and arachnids

Nature has always inspired humans in creating innovative tools. Arachnids and insects show exceptional and functional sensory receptors at a small scale. Air flow mechanoreceptors, commonly called trichobothria, are used in different shapes and sizes by several arachnid species. Some trichobothria appear to be sensitive to low-frequency near-field acoustic signals. Moreover, it is speculated that from this structure other sensing mechanisms (e.g., acceleration, temperature, etc.) are derived.

The goal of this work is to develop flat hair-like sensors inspired by the adult Buthus occitanus scorpion, that can react to either airflow or acoustic narrow frequency bands. A sensor that responds to airflow has been developed and realized using multi-material additive manufacturing (AM), also known as 3D-printing. Furthermore, using the same production technique, it is possible to create sensor structures that react to sound.

The sensors show different narrow frequency bands responses based on differences in shape and size of the artificial hair. While the structure aimed at sensing airflow shows visible movement when simply blowing on it. The 3D printed structures were successfully coated with metal and the conversion of their mechanical movements into an electric signal was achieved. Further work is being conducted to improve their electric response.