Dynamic Analysis of a Microscale Cricket Filiform Hair Socket

Filiform hairs of crickets are of great interest to engineers because of their highly sensitive response to low velocity air currents. In this study, the cercal sensory system of a common house cricket has been analyzed. The sensory system consists of two antennae like appendages called cerci that are situated at the rear of the cricket’s abdomen. Each cercus is covered with 500–750 flow sensitive hairs that are embedded in a complex viscoelastic socket that acts as a spring -dashpot system and guides the movement of the hair. When the hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron and the combined spiking activity of all hairs are extracted by the cercal sensory system. The hair has been experimentally studied by few researchers though its characteristics are not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint. Therefore, this study aims to understand the dynamic response of socket and its interaction with the filiform hair. First, a 3D Finite Element Analysis (FEA) model, representing hair and hair-socket, has been developed. Then the dynamic analysis is conducted utilizing the appropriate load and boundary conditions based on the physical conditions that an insect experiences. These numerical analyses aid to understand the dynamic response of the hair and hair-socket system. The operating principles of the hair and hair-socket could be used for the design of highly responsive MEMS devices such as fluid flow sensors or micro-manipulators.

Static Analysis of a Microscale Cricket Filiform Hair Socket

Filiform hairs of crickets are of great interest to engineers because of their highly sensitive response to low velocity air currents. In this study, the cercal sensory system of a common house cricket has been analyzed. The sensory system consists of two antennae like appendages called cerci that are situated at the rear of the cricket’s abdomen. Each cercus is covered with 500–750 flow sensitive hairs that are embedded in a complex viscoelastic socket that acts as a spring -dashpot system and guides the movement of the hair. When the hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron and the combined spiking activity of all hairs are extracted by the cercal sensory system. The hair has been experimentally studied by few researchers though its characteristics are not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint. Therefore, this study aims to understand the socket’s behavior and its interaction with the filiform hair by conducting static analysis. First, a 3D Finite Element Analysis (FEA) model, representing hair and hair-socket, has been developed. Then the static analysis is conducted utilizing the appropriate load and boundary conditions based on the physical conditions that an insect experiences. These numerical analyses aid to understand the deformation mechanism the hair and hair-socket system. The operating principles of the hair and hair-socket could be used for the design of highly responsive MEMS devices such as fluid flow sensors or micro-manipulators.

Model Development and Analysis of a Cricket Filiform Hair Socket Under Low Velocity Air Currents

Cricket filiform hairs are very sensitive to air currents in the animal’s immediate environment generated by movement of other animals or objects. When an air current is experienced by the animal, filiform hairs located on a pair of abdominal appendages called cerci deflect from their original position, activating the sensing mechanism. Though the flow sensing mechanism of the hair has been studied previously and flow sensors have been fabricated based on the same principle, the socket structure in which the hair base sits and which encompasses the hair below the skin of the cricket has not been characterized in terms of deformation and stress transfers. This paper presents a preliminary study on the response of the socket under a given loading or displacement the hair experiences. If the socket is characterized well, the mechanical principles can be applied in the design of a highly-responsive MEMS senor.

Modeling Insect Filiform Hair Motion Using the Penalty Immersed Boundary Method

Many insects are able to sense their surrounding fluid environment through induced motion of their filiform hairs. The mechanism by which the insect can sense a wide range of input signals using the canopy of filiform hairs of different length and orientation is of great interest. Most of the previous filiform hair models have focused on a single, rigid hair in an idealized air field. We have developed [1] a model for a canopy of filiform hairs that are mechanically coupled to the surrounding air. The model equations are based on the penalty immersed boundary method. The key difference between the penalty immersed boundary method and the traditional immersed boundary method is the addition of forces to account for density differences between the immersed solid (the filiform hairs) and the surrounding fluid (air). In this work we validate the model by comparing the model predictions to experimental results on cricket Acheta domestica cercal system.