Design methodology for the development of variable stiffness devices based on layer jamming transition

Variable stiffness mechanisms as Jamming Transition draw huge attention recently in Soft Robotics. This paper proposes a comprehensive design methodology for developing variable stiffness devices based on layer jamming. Starting from pre-existing modelling, we highlight the design parameters that should be considered, extracting them from literature and our direct experience with the phenomenon. Then we validated the methodology applying the design process to previous layer jamming cases presented in literature. The comparison between the results obtained from our methodology and those presented in the analyzed previous works highlights a good predictive capability, demonstrating that this methodology can be used as a valid tool to design variable stiffness devices based on layer jamming transition. Finally, in order to provide the scientific community with an easily usable tool to design variable stiffness structures based on layer jamming transition, we have elaborated a Matlab script that guides the user through the main design parameters implementing the proposed methodology in an interactive process

A new algorithm for the identification of dives reveals the foraging ecology of a shallow-diving seabird using accelerometer data

The identification of feeding events is crucial to our understanding of the foraging ecology of seabirds. Technology has made small devices, such as time-depth recorders (TDRs) and accelerometers available. However, TDRs might not be sensitive enough to identify shallow dives, whereas accelerometers might reveal more subtle behaviours at a smaller temporal scale. Due to the limitations of TDRs, the foraging ecology of many shallow-diving seabirds has been poorly investigated to date. We thus developed an algorithm to identify dive events in a shallowdiving seabird species, the Scopoli’s shearwater, using only accelerometer data. The accuracy in the identification of dives using either accelerometers or TDRs was compared. Furthermore, we tested if the foraging behaviour of shearwaters changed during different phases of reproduction and with foraging trip type. Data were collected in Linosa Island (35°51′33″N; 12°51′34″E) from 12 June to 8 September 2015 by deploying accelerometer data loggers on 60 Scopoli’s shearwaters. Four birds were also equipped with TDRs. TDRs recorded only 17.7% of the dives detected by the accelerometers using the algorithm. A total of 82.3% of dives identified by algorithm were too short or shallow to be detected by TDRs. Therefore, TDRs were not accurate enough to detect most of the dives in Scopoli’s shearwaters, which foraged mostly close to the sea surface. Our data showed that birds performed shorter foraging trips and dived more frequently in the early chick-rearing period compared with the late chick-rearing and incubation phases. Furthermore, parents dived more frequently during short foraging trips. Our results suggest that Scopoli’s shearwaters maximised their foraging effort (e.g. number of dives, short trips) during shorter foraging trips and during early chick-rearing

One-shot additive manufacturing of robotic finger with embedded sensing and actuation

A main challenge in the additive manufacturing (AM) field is the possibility to create structures with embedded actuators and sensors: addressing this requirement would lead to a reduction of manual assembly tasks and product cost, pushing AM technologies into a new dimension for the fabrication of assembly-free smart objects. The main novelty of the present paper is the one shot fabrication of a 3D printed soft finger with an embedded shape memory alloy (SMA) actuator and two different 3D printed sensors (strain gauge and capacitive force sensor). 3D printed structures, fabricated with the proposed approach, can be immediately activated after their removal from the build plate, providing real-time feedback because of the embedded sensing units. Three different materials from two nozzles were extruded to fabricate the passive elements and sensing units of the proposed bioinspired robotic finger and a custom-made Cartesian pick and place robot (CPPR) was employed to integrate the SMA spring actuator into the 3D printed robotic finger during the fabrication processes. Another novelty of the present paper is the direct integration of SMA actuators during the 3D printing process. The low melting thermoplastic polycaprolactone (PCL) was extruded: its printing temperature of 70 °C is lower than the SMA austenitic start temperature, preventing the SMA activation during the manufacturing process. Two different sensors based on the piezoresistive principle and capacitive principle were studied, 3D printed and characterized, showing respectively a sensitivity ratio of change in resistance to finger bending angle to be 674.8 Ω∘Angle and a capacitance to force ratio of 0.53pFN . The proposed manufacturing approach paves the way for significant advancement of AM technologies in the field of smart structures with embedded actuators to provide real-time feedback, offering several advantages, especially in the soft robotics domain

Identification of subgroups of early breast cancer patients at high risk of nonadherence to adjuvant hormone therapy: results of an italian survey.

The aim of this study was the identification of subgroups of patients at higher risk of nonadherence to adjuvant hormone therapy for breast cancer. Using recursive partitioning and amalgamation (RECPAM) analysis, the highest risk was observed in the group of unmarried, employed women, or housewives. This result might be functional in designing tailored intervention studies aimed at improvement of adherence. Background: Adherence to adjuvant endocrine therapy (HT) is suboptimal among breast cancer patients. A high rate of nonadherence might explain differences in survival between clinical trial and clinical practice. Tailored interventions aimed at improving adherence can only be implemented if subgroups of patients at higher risk of poor adherence are identified. Because no data are available for Italy, we undertook a large survey on adherence among women taking adjuvant HT for breast cancer. Patients and Methods: Patients were recruited from 10 cancer clinics in central Italy. All patients taking HT for at least 1 year were invited, during one of their follow-up visit, to fill a confidential questionnaire. The association of sociodemographic and clinical characteristics of participants with adherence was assessed using logistic regression. The RECPAM method was used to evaluate interactions among variables and to identify subgroups of patients at different risk of nonadherence. Results: A total of 939 patients joined the study and 18.6% of them were classified as nonadherers. Among possible predictors, only age, working status, and switching from tamoxifen to an aromatase inhibitor were predictive of nonadherence in multivariate analysis. RECPAM analysis led to the identification of 4 classes of patients with a different likelihood of nonadherence to therapy, the lowest being observed in retired women with a low level of education, the highest in the group of unmarried, employed women, or housewives. Conclusion: The identification of these subgroups of “real life” patients with a high prevalence of nonadherers might be functional in designing intervention studies aimed at improving adherenc

Distinct profile of inflammatory and remodelling biomarkers in sputum of severe asthmatic patients with or without persistent airway obstruction

Background: Both inflammatory and remodelling processes are associated with irreversible airway obstruction observed in severe asthma. Our aim was to characterize a group of severe asthmatic patients with or without persistent airway obstruction in relation to specific sputum inflammatory and remodelling biomarkers. Methods: Forty-five patients under regular high-dose inhaled corticosteroid/ß-2agonist treatment were studied, after a follow-up period of at least 2 years, with a minimum of 4 visits. Periostin, TGF-ß, RANTES, IL-8, GM-CSF, FGF-2, and cell counts were measured in induced sputum. Serum periostin was also measured. Results: Sputum induction was successfully performed in all but 5 patients. There were no significant differences in demographic and clinical data between patients with non-persistent obstruction (NO: FEV1/VC>88%pred.) and those with persistent obstruction (O: a not completely reversible obstruction with FEV1/VC<88%pred. at each visit before the study visit). Patients with persistent obstruction had significantly higher sputum periostin and TGF-ß concentrations than NO patients and a trend of higher serum periostin levels. GM-CSF and FGF-2 were significantly increased in NO compared to O patients. No differences between groups were found for RANTES, IL-8 and differential cell counts. Sputum periostin inversely correlated with functional parameters (prebronch. FEV1: rho = −0.36, p < 0.05; postbronch. FEV1: rho = −0.33, p = 0.05). Patients with high sputum periostin concentration (>103.3 pg/ml: median value) showed an absolute number of sputum eosinophils significantly higher than patients with low sputum periostin; this behavior was unobserved when serum periostin was considered. Conclusions: Only periostin and TGF-ß identified a subgroup of severe asthmatic patients with persistent airway obstruction. Sputum periostin was also inversely associated with FEV1 and proved to be a more sensitive biomarker than serum periostin to identify severe asthmatics with higher sputum eosinophilia

Silicone Based Capacitive E-Skin Sensor for Soft Surgical Robots

In this extended abstract, we present a soft stretchable multi-modal capacitive skin sensor that can be used for exteroception and proprioception in soft surgical manipulators. A soft skin prototype was made using Ecoflex, embedding three conductive carbon grease terminal layers. This soft skin is capable of measuring stretch and touch simultaneously. The soft skin measures uniaxial stretches from 1 to 1.2475 within an error range of 2.6% and can also quantify as well as localize local indentation. An algorithm is developed that decouples local change, i.e., due to indentation, from global strain, due to stretch. An experimental study was conducted; results are presented

The Restoration Interventions of “Forte Marghera” in Venice

In the framework of the Strategic Masterplan Cultural Heritage 2014-2018 of the Italian Ministry of Culture, a specific attention for the strengthening and constitution of relevant urban cultural centers is sought through the restoration and re-use of structural complexes of great architectural and historic value such as the case of Forte Marghera (Marghera Fort) of Venice. The need to build a fortress at the point where the mainland approached Venice was understood, after the fall of the “Serenissima” Republic (1797), by the Austrian Empire. The fort was therefore built in a marshy area on the edge of the Venice lagoon, crossed by a maze of canals. The works started in 1805. On the area there was already the old village of Malghera, home to warehouses and customs, which was incorporated into the Fort. However, the return of Napoleon's troops in 1806 surprised the works still in a early stage. The fortified work was then revised according to the plans of the French architect Marescò and conducted under the guidance of the general and military engineer François-Joseph Chaussegros de Léry and later the Chasseloup. The most significant buildings still present in the fortress – object of the current restoration works - are the two French barracks (1805-1814), located on the front near the dock. They are two-storey brickwork masonry structures with a 83x15 m rectangular plan and perimeter walls reaching a 3 m thickness, provided with decorative elements made of Istria stone. Visible decay is present in both two massive buildings, due to differential settlements mainly visible the long sides of both buildings, especially affecting the West one, also partially subjected to local collapse. A wide investigation campaign, aiming to the adequate characterization of the constituting materials and building techniques, was carried out in order to properly feed the design of conservative restoration interventions. Results indicate the use of good quality materials and proper layout also in the foundation system, indicating in the poor soil mechanical characteristics the main structural deficiency leading to the visible settlements. To date, the detailed design stage was reached for just one of the three buildings involved in the restoration, while the two remaining buildings are still in a preliminary design phase

Kinematic Control and Obstacle Avoidance for Soft Inflatable Manipulator

© Springer Nature Switzerland AG 2019. In this paper, we present a kinematic control and obstacle avoidance for the soft inflatable manipulator which combines pressure and tendons as an actuating mechanism. The position control and obstacle avoidance took inspiration from the phenomena of a magnetic field in nature. The redundancy in the manipulator combined with a planar mobile base is exploited to help the actuators stay under their maximum capability. The navigation algorithm is shown to outperform the potential-field-based navigation in its ability to smoothly and reactively avoid obstacles and reach the goal in simulation scenarios