Search Results (4)

This paper presents the ultrastructure morphology of Nabis rugosus trichoid sensilla using SEM and TEM data, along with a two-dimensional model of the trichoid sensilla developed in Amira software. The SEM images show the shape and scattering of the trichoid mechanosensilla over the N. rugosus flagellomere. The TEM images present the ultrastructural components, in which the hair rises from the socket via the joint membrane. The dendrite sheath is connected at the base of the hair shaft, surrounded by the lymph space and the socket septum. This dendrite sheath contains a tubular body with microtubules separated by the membrane (M) and granules (Gs). This study presents a model and simulation of the trichoid sensilla sensing mechanism, in which the hair deflects due to the application of external loading above it and presses the dendrite sheath attached to the hair base. The dendrite sheath is displaced by the applied force, transforming the transversal loading into a longitudinal deformation of the microtubules. Due to this longitudinal deformation, electric potential develops in the microtubule’s core, and information is delivered to the brain through the axon. The sensilla’s pivot point or point of rotation is presented, along with the relationship between the hair shaft length, the pivot point, and the electric potential distribution in the microtubules. This study’s results can be used to develop ultra-sensitive, bioinspired sensors based on these ultrastructural components and their biomechanical studies. Full article

The present study aims to investigate the morphological features of the antennal sensilla by using SEM and TEM. The construction of a 3D model of trichoideum sensillum using Amira software is presented in this paper. Five sensillum types, namely trichoideum, chaeticum, campaniformium, coeloconicum, and basiconicum, were recorded. This model exhibits the mechanosensillum components, including the embedded hair in a socket attached by the joint membrane and the dendrite connected to the hair base passing through the cuticle layers. TEM images present the dendrite way, micro-tubules inside the dendritic sheath, and terminal structure of the tubular dendrite body and so-called companion cells included in the receptor, e.g., tormogen and trichogen. The parameters noted for the external structure and ultrastructure of the mechano-receptor indicate that they are specific to a particular type of sensillum and would be useful in developing the model for a biosensor. Results show that bio-inspired sensors can be developed based on morphological and ultrastructural studies and to conduct mechanical studies on their components. Full article

Fiber-reinforced polymer (FRP) matrix materials are quickly being investigated for application in concrete construction repair, reinforcement, and refurbishment. The technology has progressed to the point that its future acceptance is mainly reliant on the availability of established design guidelines based on recognized performance criteria, as well as the cost competitiveness of these technologies in contrast to conventional rehabilitation methods. The goal of this study is to evaluate the different functional grades of adhesives throughout bond length for bonded socket joints of laminated FRP composite pipes. Damage development resistance is high with a functionally graded FRP composite socket joint, as shown. To extend the service life of the structure, the joint designer should use an FRP composite socket joint with a functionally graded adhesive (FGA). Full article

Mechanoreceptors of the insect play a vital role for the insect to sense and monitor the environmental parameters, like flow, tactile pressure, etc. This paper presents the studies made on the morphology of the mechanoreceptor of the insect Blattella asahinai (scientific name of cockroach) that is a hair-like structure known as trichoid sensilla, by scanning electron microscope and confocal laser microscope. The scanned images show the details of sensilla components in which the hair is embedded in the sockets, which are connected with the cuticle and joint membrane, where the dendrite touches at the base of the hair passing through the cuticle layers. The images also show that the tubular bodies and microtubules are tightly compacted inside the dendrite. This paper presents the details of how the sensilla work when an external stimulus act on them. The hair deflects with the disturbance of the cuticle and joint membrane, and this deformed hair leans on the dendrite, which is attached at the base of the hair that in turn presses the tubular bodies and microtubules, which develop negative ions passing down through the dendrite to the neuron, which provides information as an electric signal to the brain of the insect so that it responds for necessary action. Based on the morphological studies, sensing mechanism, material properties of the components, and design principles will be evolved for the development of an artificial bio-inspired sensor. A solid works model of the sensilla is also presented. Full article