9 research outputs found
Development of a gripper for garment handling designed for additive manufacturing
The paper presents how a robotic gripper specific for grasping and handling of textiles and soft flexible layers can be miniaturized and improved by polymeric additive manufacturing-oriented re-design. Advantages of polymeric additive manufacturing are to allow a re-design of components with integrated functions, to be cost-effective equipment for small batches production and the availability of suitable materials for many applications. The drawback is that for design validation extended testing is still necessary because of lacks in standardization and that the mechanical properties are building parameters dependent. The outcomes are a lower complexity of the design overall and lower number of components. These are pursued taking advantage of the anisotropy of the additive manufacturing processed polymer and assigning appropriate shapes and linkages in the mechanisms. Set of common materials (polylactide, polyethylene terephthalate, acrylonitrile butadiene styrene) and technical (acrylonitrile styrene acrylate, polycarbonate/polybutylene terephthalate blend) are tested to obtain data for the modelling
Dispositivo di presa per l'afferraggio di pezzi, particolarmente per robot e sistemi di automazione
ADDITIVE MANUFACTURING PROCESS PARAMETER INFLUENCE ON MECHANICAL STRENGTH OF ADHESIVE JOINTS, PRELIMINARY ACTIVITIES
open7The work illustrates how building parameters of the Additive Manufacturing (AM) process fused filament
fabrication can affect not only the mechanical properties [1] but also the surface wettability and morphology.
Wettability and morphology are relevant factors in bonded joints performance [2]. Advantages of polymeric
AM are to allow a re-design of components with locally controlled properties [3] and integrated functions.
Major limitations are related to the lack of material testing standardization and constraints due to the build
volume and to the object orientation for printability: the latter problem can be addressed with the use of
bonded joints that allow to create bigger assemblies from smaller parts optimally designed to take advantage
of the anisotropy of the material and without the structural drawbacks due to other joining method, such as
stress concentration in bolted joints. As for the Mechanical properties, they are obtained with uniaxial tensile
tests using MaCh3D [4], an innovative cost effective solution for materials testing. The as built surface
properties are investigated quantitatively and qualitatively using a plate specimen of 15 × 15 × 1.2 mm.
Roughness parameters are measured by surface scanning with a CCI Taylor-Hobson 3D optical profilometer
while contact angle values between specimens and a drop of Milli-Q water are measured in order to evaluate
wettability. Different materials, such as ABS and PLA, are characterized at different combinations of nozzle
temperature, print speed and layer thickness. The analysis of the collected data provide information on how
building parameters can modify two fundamental aspects in adhesive joints such as surface roughness and
wettability in order to maximize joint performance.openM. Frascio, L. Bergonzi, F. Moroni, A. Pirondi, M. Avalle, M. Monti, M. VettorFrascio, M.; Bergonzi, L.; Moroni, F.; Pirondi, A.; Avalle, M.; Monti, M.; Vettor, M
Application of a Biphasic Actuator in the Design of the CloPema Robot Gripper
The paper (a first version of this work was presented in Aug. 2014 at ASME-DETC in Buffalo, NY) describes a novel robot gripper for garment handling. The device has been designed, developed, prototyped, and tested within the CloPeMa European Project creating a robot system for automated manipulation of clothing and other textile items. The gripper has two degrees of freedom (dof) and includes both rigid and flexible elements. A variable-stiffness actuator has been implemented to add controlled compliance in the gripper's operation allowing the combining of various grasping and manipulation tasks. First, we analyze the specific application-determined task requirements, focusing on the need for adaptive flexibility and the role of compliant elements in the design. The chosen solution is a simple planar mechanism, equipped with one standard and one variablestiffness actuator. The mechanical design of the gripper, including the hydraulic system used in the biphasic actuator, is outlined, and the control architecture, using sensor feedback, is described
The Effect of Latent Toxoplasma gondii Infection on the Immune Response in HIV-Infected Patients
A relationship between latent toxoplasmosis and the immune system during HIV disease is poorly understood. Therefore, the aim of this follow-up study was to characterize immunological parameters in HIV-infected patients with latent toxoplasmosis and noninfected individuals. A total of 101 HIV-infected patients were enrolled in the study. The patients were classified into two groups based on anti-Toxoplasma gondii antibodies: a group of 55 toxoplasma-positive persons (TP) and a group of 46 toxoplasmanegative persons (TN). Absolute counts of several lymphocyte subsets decreased in the TP group, namely, T cells ( = 0.007), B cells ( = 0.002), NK cells ( = 0.009), CD4 T cells ( = 0.028), and CD8 T cells ( = 0.004). On the other hand, the percentage of CD8 T cells expressing CD38 and HLA-DR significantly increased during the follow-up in the TP group ( = 0.003, = 0.042, resp.) as well as the intensity of CD38 and HLA-DR expression (MFI) on CD8 T cells ( = 0.001, = 0.057, resp.). In the TN group, analysis of the kinetics of immunological parameters revealed no significant changes over time. In conclusion, the results suggest that latent T. gondii infection modulates the immune response during HIV infection