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Your search keyword '"Lakhtakia, Akhlesh"' showing total 152 results
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152 results on '"Lakhtakia, Akhlesh"'

9. Biological approaches to electrical conductance in non-metallic materials for engineered products

Author

Wandall, Allan P., Lenau, Torben A., Lakhtakia, Akhlesh, Martín-Palma, Raúl J., Knez, Mato, and Lakhtakia, Akhlesh

Abstract

The use of electricity is so pervasive that life without it is unimaginable today. The scope of electricity is even widening to encompass wearables and draperies in domestic and professional surroundings. The typical way of conducting electricity is through metallic wires and conduits, which often are integrated permanently into engineered products. This means that we have more and more products with mixed materials that are difficult to recycle, thereby creating a major bottleneck towards the achievement of sustainable urban and rural environments. If electricity could be conducted in another way, new design options would become possible. The bioworld offers ways for conducting electricity without metallic interconnects. Examples range from electric discharges by electric eels to electrolocation by fish to bacterial protein networks that conduct electrons. A review of electrical conduction mechanisms in the bioworld suugests the feasibility of incorporating the underlying bioworld principles in engineered products.

Published
2022

26. Design and evaluation of a wasp-inspired steerable needle

Author

Scali, M., Kreeft (student), Davey, Breedveld, P., Dodou, D., Knez, Mato, Lakhtakia, Akhlesh, and Martín-Palma, Raúl J.

Subjects
0209 industrial biotechnology, Materials science, business.industry, deflection, Medical needles, steerable needles, 0206 medical engineering, Medical practice, Nanotechnology, 02 engineering and technology, Conical surface, steering curvature, Curvature, 020601 biomedical engineering, Imaging phantom, 020901 industrial engineering & automation, Optics, Deflection (engineering), biologically inspired design, business, Bifurcation
Abstract

Flexible steerable needles can follow complex curved paths inside the human body. In a previous work, we developed a multiple-part steerable needle prototype with a diameter of 1.2 mm, inspired by the ovipositor of parasitoid wasps. The needle consisted of seven nickel-titanium longitudinally aligned wires held together at the tip by a cylindrical ring with seven holes. The steerability of the needle was evaluated in a gelatin phantom and was found to be lower than that of other steerable needles in the literature. One possible cause of this limited steerability is that during motion the wires tend to separate from each other (i.e., bifurcate). Our aim here was to reduce bifurcation in order to increase the steering curvature of the needle, while keeping the diameter around 1.5 mm, and thus compatible with needles used in medical practice. To achieve that, we changed the shape of the ring from cylindrical to conical. We evaluated the steering performance in gelatin, using the conical ring in two configurations: (1) with the apex of the cone towards the needle tip, so that the wires converge, thus expected to reduce bifurcation, (2) with the apex of the cone placed towards the needle base, so that the wires diverge, thus expected to magnify bifurcation. Results showed that the diverging ring generated larger steering curvatures. We can conclude that reducing the bifurcation of the wires is not enough for increasing the steering curvature and that inducing this same phenomenon instead could actually lead to higher curvatures.

Published
2017

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