Search results for "Soft robotics"

Stiffness Estimation and Adaptive Control for Soft Robots

2022

Nonostante la sorprendente crescita nello sviluppo dei robot ispirati alla natura, tra cui i cosiddetti soft robot, il potenziale di questi sistemi, che hanno intrinseche capacità di adattamento, non è ancora stato sfruttato a pieno. La ricerca ha principalmente considerato il controllo in retroazione della posizione dei giunti del robot, lasciando la gestione della cedevolezza di questi ultimi ancora in anello aperto. Peraltro, le attuali limitazioni nel processo di produzione degli attuatori a cedevolezza variabile e l'inevitabile variabilità nel tempo degli elementi elastici costitutivi, i quali sono soggetti ad usura e deformazione plastica, rendono il problema della determinazione prec…

On the Stability of the Soft Pendulum With Affine Curvature: Open-Loop, Collocated Closed-Loop, and Switching Control

2022

This letter investigates the stability properties of the soft inverted pendulum with affine curvature - a template model for nonlinear control of underactuated soft robots. We look at how changes in physical parameters affect stability and equilibrium. We give conditions under which zero dynamics corresponding to a collocated choice of the output is (locally or globally) stable or unstable. We leverage these results to design a switching controller that stabilizes a class of nonlinear equilibria of the pendulum, which can drive the system from one equilibrium to another.

Solution-processed transparent ferroelectric nylon thin films

2019

We have developed a method to solution process strongly hydrogen-bonded odd nylons into ferroelectric thin films.

Design and Characterization of a Miniature Hydraulic Power Supply for High-Bandwidth Control of Soft Robotics

2020

Soft robotics holds enormous promise for a wide class of applications. However, system controllability, bandwidth, portability, and energy efficiency of soft robot power supplies are often inadequate. Soft robotics desperately needs improved solutions to drive soft actuators either pneumatically or hydraulically. This research paper offers a contribution to bridge this gap. It deals with small-scale power supplies for hydraulically-driven soft robots based on fluidic elastomer actuators in the power range 5-400 W. A design procedure for such power supplies is developed with an emphasis on high-bandwidth control. The performance requirements are established based on a literature survey, and …

Paediatric solid oral dosage forms for combination products: Improving in vitro swallowability of minitablets using binary mixtures with pellets

2023

There is a growing interest in determining and improving the acceptability of solid oral dosage forms (SODF) in paediatric populations. Combination products can be an interesting solution to combine two active pharmaceutical ingredients. This study shows that binary mixture of paediatric SODF could enhance formulation swallowability and palatability. Using the Paediatric Soft Robotic Tongue (PSRT) – an in vitro device inspired by the anatomy and physiology of 2-year-old children – we investigated the oral phase of swallowing of multi-particulate formulations, i.e., pellets (350 and 700 µm particles), minitablets (MTs, 1.8 mm), and their binary mixtures (BM), by measuring the oral swallowing…

Switchable surface structured hydrogel coatings

2017

Switchable surface structures based on hydrogels are an emerging field in material science, microfluidics, soft robotics and anti-fouling. Here, we describe a novel method that uses a photo-cross-linkable terpolymer to create a hydrogel coating with a switchable surface structure. The terpolymer is based on poly(N-isopropylacrylamide) (PNIPAm) and it is shown that simple coating technologies like slit die coating can be used under ambient conditions. It is also shown that the swelling ratio of the coating is controlled by the energy dose of ultraviolet (UV) light. Simple and complex surface structures were created using respectively single or multiple UV illumination steps through masks and…

Wavelength-Gated Adaptation of Hydrogel Properties via Photo-Dynamic Multivalency in Associative Star Polymers.

2020

Abstract Responsive materials, such as switchable hydrogels, have been largely engineered for maximum changes between two states. In contrast, adaptive systems target distinct functional plateaus between these maxima. Here, we demonstrate how the photostationary state (PSS) of an E/Z‐arylazopyrazole photoswitch can be tuned by the incident wavelength across a wide color spectrum, and how this behavior can be exploited to engineer the photo‐dynamic mechanical properties of hydrogels based on multivalent photoswitchable interactions. We show that these hydrogels adapt to the wavelength‐dependent PSS and the number of arylazopyrazole units by programmable relationships. Hence, our material des…

A novel soft robotic pediatric in vitro swallowing device to gain insights into the swallowability of mini-tablets Authors

2022

Adaptive Control of Soft Robots Based on an Enhanced 3D Augmented Rigid Robot Matching

2021

Despite having proven successful in generating precise motions under dynamic conditions in highly deformable soft-bodied robots, model based techniques are also prone to robustness issues connected to the intrinsic uncertain nature of the dynamics of these systems. This letter aims at tackling this challenge, by extending the augmented rigid robot formulation to a stable representation of three dimensional motions of soft robots, under Piecewise Constant Curvature hypothesis. In turn, the equivalence between soft-bodied and rigid robots permits to derive effective adaptive controllers for soft-bodied robots, achieving perfect posture regulation under considerable errors in the knowledge of …