scholarly journals DESIGN OF A SIMPLIFIED 3D-PRINTED ARTIFICIAL UNDERACTUATED HAND

2020 ◽  
Vol 1 ◽  
pp. 1027-1036
Author(s):  
A. Orabona ◽  
A. Palazzi ◽  
S. Graziosi ◽  
F. Ferrise ◽  
M. Bordegoni

AbstractThe recent interest in human-robot interaction requires the development of new gripping solutions, compared to those already available and widely used. One of the most advanced solutions in nature is that of the human hand, and several research contributions try to replicate its functionality. Technological advances in manufacturing technologies and design tools are opening possibilities in the design of new solutions. The paper reports the results of the design of an underactuated artificial robotic hand, designed by exploiting the benefits offered by additive manufacturing technologies.

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 617
Author(s):  
Ruben Foresti ◽  
Benedetta Ghezzi ◽  
Matteo Vettori ◽  
Lorenzo Bergonzi ◽  
Silvia Attolino ◽  
...  

The production of 3D printed safety protection devices (SPD) requires particular attention to the material selection and to the evaluation of mechanical resistance, biological safety and surface roughness related to the accumulation of bacteria and viruses. We explored the possibility to adopt additive manufacturing technologies for the production of respirator masks, responding to the sudden demand of SPDs caused by the emergency scenario of the pandemic spread of SARS-COV-2. In this study, we developed different prototypes of masks, exclusively applying basic additive manufacturing technologies like fused deposition modeling (FDM) and droplet-based precision extrusion deposition (db-PED) to common food packaging materials. We analyzed the resulting mechanical characteristics, biological safety (cell adhesion and viability), surface roughness and resistance to dissolution, before and after the cleaning and disinfection phases. We showed that masks 3D printed with home-grade printing equipment have similar performances compared to the industrial-grade ones, and furthermore we obtained a perfect face fit by customizing their shape. Finally, we developed novel approaches to the additive manufacturing post-processing phases essential to assure human safety in the production of 3D printed custom medical devices.


Author(s):  
Mahdi Haghshenas-Jaryani ◽  
Muthu B. J. Wijesundara

This paper presents the development of a framework based on a quasi-statics concept for modeling and analyzing the physical human-robot interaction in soft robotic hand exoskeletons used for rehabilitation and human performance augmentation. This framework provides both forward and inverse quasi-static formulations for the interaction between a soft robotic digit and a human finger which can be used for the calculation of angular motions, interaction forces, actuation torques, and stiffness at human joints. This is achieved by decoupling the dynamics of the soft robotic digit and the human finger with similar interaction forces acting on both sides. The presented theoretical models were validated by a series of numerical simulations based on a finite element model which replicates similar human-robot interaction. The comparison of the results obtained for the angular motion, interaction forces, and the estimated stiffness at the joints indicates the accuracy and effectiveness of the quasi-static models for predicting the human-robot interaction.


2018 ◽  
Vol 23 (6) ◽  
pp. 2662-2670
Author(s):  
Kyeong Ha Lee ◽  
Seung Guk Baek ◽  
Hyuk Jin Lee ◽  
Hyouk Ryeol Choi ◽  
Hyungpil Moon ◽  
...  

Author(s):  
Adhau P ◽  
◽  
Kadwane S. G ◽  
Shital Telrandhe ◽  
Rajguru V. S ◽  
...  

Human robot interaction have been ever the topic of research to research scholars owing to its importance to help humanity. Robust human interacting robot where commands from Electromyogram (EMG) signals is recently being investigated. This article involves study of motions a system that allows signals recorded directly from a human body and thereafter can be used for control of a small robotic arm. The various gestures are recognized by placing the electrodes or sensors on the human hand. These gestures are then identified by using neural network. The neural network will thus train the signals. The offline control of the arm is done by controlling the motors of the robotic arm.


2020 ◽  
Vol 27 (3) ◽  
pp. 71-81
Author(s):  
Mariusz Deja ◽  
Mieczysław Stanisław Siemiątkowski ◽  
Dawid Zieliński

AbstractThe dynamic development of additive manufacturing technologies, especially over the last few years, has increased the range of possible industrial applications of 3D printed elements. This is a consequence of the distinct advantages of additive techniques, which include the possibility of improving the mechanical strength of products and shortening lead times. Offshore industry is one of these promising areas for the application of additive manufacturing. This paper presents a decision support method for the manufacturing of offshore equipment components, and compares a standard subtractive method with an additive manufacturing approach. An analytic hierarchy process was applied to select the most effective and efficient production method, considering CNC milling and direct metal laser sintering. A final set of decision criteria that take into account the specifics of the offshore industry sector are provided.


2018 ◽  
Vol 919 ◽  
pp. 222-229
Author(s):  
Jiří Šafka ◽  
Filip Veselka ◽  
Martin Lachman ◽  
Michal Ackermann

The article deals with the topic of 3D printing of pressure vessels and their testing. The main focus of the research was on a 3D model of the pressure vessel, which was originally designed for a student formula racing car project. The described virtual 3D model was designed with regard to 3D printing. The physical model was manufactured using several additive manufacturing technologies. The first technology was FDM using ULTEM 1010 material. The next technology was SLS (Selective Laser Sintering) using polyamide materials (PA3200GF and PA2220). The last technology was SLA (Stereolithography) using a polypropylene material (Durable). Experimental evaluation of the vessels was carried out by a pressure test, which verified the compactness of the 3D printed parts and their possible porosity. At the end of the article, a comparison of each printed model is made in terms of their final price and weight, together with pressure and thermal resistance.


Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5695
Author(s):  
Jaume Pujante ◽  
Borja González ◽  
Eduard Garcia-Llamas

Since the popularization of press hardening in the early noughties, die and tooling systems have experienced considerable advances, with tool refrigeration as an important focus. However, it is still complicated to obtain homogeneous cooling and avoid hot spot issues in complex geometries. Additive Manufacturing allows designing cavities inside the material volume with little limitation in terms of channel intersection or bore entering and exit points. In this sense, this technology is a natural fit for obtaining surface-conforming cooling channels: an attractive prospect for refrigerated tools. This work describes a pilot experience in 3D-printed press hardening tools, comparing the performance of additive manufactured Maraging steel 1.2709 to conventional wrought hot work tool steel H13 on two different metrics: durability and thermal performance. For the first, wear studies were performed in a controlled pilot plant environment after 800 hot stamping strokes in an omega tool configuration. On the second, a demonstrator tool based on a commercial tool with hot spot issues, was produced by 3D printing including surface-conformal cooling channels. This tool was then used in a pilot press hardening line, in which tool temperature was analyzed and compared to an equivalent tool produced by conventional means. Results show that the Additive Manufacturing technologies can be successfully applied to the production of press hardening dies, particularly in intricate geometries where new cooling channel design strategies offer a solution for hot spots and inhomogeneous thermal loads.


2019 ◽  
Vol 4 (10) ◽  
pp. 173-178
Author(s):  
André Silva ◽  
Samuel De Oliveira ◽  
Andreas Ries ◽  
Simplício A. Silva ◽  
Cícero Souto

This paper presents a robotic hand using wires with shape memory (NiTi) as non-conventional actuators. The mechanical structure of the robot hand was first designed by means of a CAD computer program and afterwards 3D printed using ABS polymer. The robotic hand was designed according to the physiological characteristics of the human hand, with particular attention to the angles formed by the phalanges of the fingers. A mechanical system accommodates the thin NiTi wires compactly, thus forming an artificial muscle. A fuzzy logic based control system allows an accurate positioning of each phalanx. The contribution of the present work to science lies in the practical implementation of known techniques and materials.


2019 ◽  
Vol 374 (1771) ◽  
pp. 20180036 ◽  
Author(s):  
Cesco Willemse ◽  
Agnieszka Wykowska

Initiating joint attention by leading someone's gaze is a rewarding experience which facilitates social interaction. Here, we investigate this experience of leading an agent's gaze while applying a more realistic paradigm than traditional screen-based experiments. We used an embodied robot as our main stimulus and recorded participants' eye movements. Participants sat opposite a robot that had either of two ‘identities’—‘Jimmy’ or ‘Dylan’. Participants were asked to look at either of two objects presented on screens to the left and the right of the robot. Jimmy then looked at the same object in 80% of the trials and at the other object in the remaining 20%. For Dylan, this proportion was reversed. Upon fixating on the object of choice, participants were asked to look back at the robot's face. We found that return-to-face saccades were conducted earlier towards Jimmy when he followed the gaze compared with when he did not. For Dylan, there was no such effect. Additional measures indicated that our participants also preferred Jimmy and liked him better. This study demonstrates (a) the potential of technological advances to examine joint attention where ecological validity meets experimental control, and (b) that social reorienting is enhanced when we initiate joint attention. This article is part of the theme issue ‘From social brains to social robots: applying neurocognitive insights to human–robot interaction’.


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