Gripe-Needle: A Sticky Suction Cup Gripper Equipped Needle for Targeted Therapeutics Delivery

This paper presents a multi-purpose gripping and incision tool-set to reduce the number of required manipulators for targeted therapeutics delivery in Minimally Invasive Surgery. We have recently proposed the use of multi-arm Concentric Tube Robots (CTR) consisting of an incision, a camera, and a gripper manipulator for deep orbital interventions, with a focus on Optic Nerve Sheath Fenestration (ONSF). The proposed prototype in this research, called Gripe-Needle, is a needle equipped with a sticky suction cup gripper capable of performing both gripping of target tissue and incision tasks in the optic nerve area by exploiting the multi-tube arrangement of a CTR for actuation of the different tool-set units. As a result, there will be no need for an independent gripper arm for an incision task. The CTR innermost tube is equipped with a needle, providing the pathway for drug delivery, and the immediate outer tube is attached to the suction cup, providing the suction pathway. Based on experiments on various materials, we observed that adding a sticky surface with bio-inspired grooves to a normal suction cup gripper has many advantages such as, 1) enhanced adhesion through material stickiness and by air-tightening the contact surface, 2) maintained adhesion despite internal pressure variations, e.g. due to the needle motion, and 3) sliding resistance. Simple Finite Element and theoretical modeling frameworks are proposed, based on which a miniature tool-set is designed to achieve the required gripping forces during ONSF. The final designs were successfully tested for accessing the optic nerve of a realistic eye phantom in a skull eye orbit, robust gripping and incision on units of a plastic bubble wrap sample, and manipulating different tissue types of porcine eye samples.

Comparison of Different Fin and Tube Compact Heat Exchanger with Longitudinal Vortex Generator in CFU-CFD Configurations

Over the last decades several studies have searched for improved Fin and Tube Heat Exchanger (FTHE) designs capable of providing the best thermo-hydraulic performance. The present study aims at quantifying and comparing the thermo-hydraulic performance of different FTHE configurations. Six different designs were analyzed. The first FTHE consisted of an in-line circular tube arrangement and the last one was a FTHE with staggered oval tube with two pairs of Delta Winglet Vortex Generators (DWVG) in common flow up–common flow down (CFU-CFD) configuration. The best performance was obtained using DWVG in CFU-CFD orientation. This configuration enabled a 90% increase of the thermal performance factor when compared with the first case, using only two pairs of vortex generator´s per tube.

Simulation of the Optimal Refrigerated Floor Design for Ice Rinks

A good design of the ice rink floor could save a great deal of capital and operational costs for hockey arenas. This ice rink floor design focuses on a cost-effective tube arrangement and an optimal concrete coverage over the tubes that could provide sufficient heat transfer rate between the coolant and the freezing ice. This paper reports a theoretical model to simulate the heat transfer characteristic of a different tube diameter, spacing distance, and thickness of the concrete coverage of the tubes of an ice rink. In addition, calcium chloride and ethylene glycol with water solutions are compared to figure out the pros and cons of these two secondary coolants. This model prediction is compared to the typical ice floor arrangement in order to determine the best floor construction scenario.