Simulation and development of paper-based actuators

Soft robots have become an attractive research topic for opening new doors for robots' limitations by being flexible, light, and small and with the ability to have an adaptable shape. An essential component in a soft robot is the soft actuator, which provides the system with a deformable body and allows it to interact with the environment to achieve the desired actuation pattern. Among the various materials used in soft actuators, paper-based actuators have special attention because paper is an abundant, lightweight, and biodegradable material. This work illustrates an insight into the soft actuators field and focuses on developing unique paper-based actuators applying the microwave heat for a liquid-vapor phase transition, in this case, water. This document focuses on the study of different designs, materials, and thick-nesses by changing the paper, elastomer, and double-sided tape.Os robôs flexíveis tornaram-se um tópico de pesquisa atraente por abrirem novas portas para as limitações dos robôs por serem flexíveis, leves e pequenos e com a capacidade de ter uma forma adaptável. Um componente essencial em um robô flexível é o atuador flexível, que fornece ao sistema um corpo deformável e permite que este interaja com o ambiente para atingir o movi-mento desejado. Dos vários materiais usados em atuadores flexíveis, os atuadores baseados em papel têm especial atenção porque o papel é um material abundante, leve e biodegradável. Este trabalho ilustra uma visão da área de atuadores flexíveis e foca no desenvolvimento de atuadores únicos baseados em papel , aplicando o calor de microondas para uma transição de fase líquido-vapor, neste caso, água. Este documento mostra o estudo de diferentes designs, ma-teriais e espessuras, alterando o papel, elastómero e fita dupla-face

Development of paper-based hygro-mechanical systems for liquid characterization

Over the past few years, paper-based microfluidics systems have been extensively applied to perform different analytical tasks including detection and quantification of the specific analyte. Few works have reported the use of paper as a structural element to develop both sensors and actuators. These devices are extremely useful as they are inexpensive, easy to fabricate, disposable and portable. However, other features of paper that can be applied to develop new sensing principles have not been explored. Paper is a hygroscopic material that enables the generation of motion by hygromorphism. In this work, paper-based hygro-mechanical systems (PB-HMS) for liquid characterization are developed. The configuration of the developed PB-HMS is formed by the interaction of a paper-based cantilever beam and a liquid droplet. The paper-based cantilever beam acts as a hygroscopic sensitive element, while the liquid droplet triggers the bending response of the PB-HMS. These systems do not require any external source of energy to stimulate the sensing element (i.e. electric or magnetic field) as their interaction with the liquid droplet activates the motion. iv In addition, different gaps in the knowledge found in the literature were addressed to develop the PB-HMS. They are described as follows. First, an imbibition model based on Richards’ equation is developed in this thesis to predict liquid imbibition in complex paper-based networks. Second, a dimensionless stress-imbibition model including three main nonlinearities (imbibition, swelling and softening) is developed in this work. Third, the influences of such nonlinearities on the characteristic hygro-mechanical bending response of paper-based beams are studied. Fourth, the design of the PB-HMS is performed in order to extract information from the systems using their dynamic response. Finally, a method to quantify the dynamic performance of the PB-HMS in order to characterize liquid is developed

Development, evolution and genetic analysis of C. elegans-inspired foraging algorithms under different environmental conditions

In this work 3 minimalist bio-inspired foraging algorithms based on C. elegans’ chemotaxis and foraging behaviour were developed and investigated. The main goal of the work is to apply the algorithms to robots with limited sensing capabilities. The refined versions of these algorithms were developed and optimised in 22 different environments. The results were processed using a novel set of techniques presented here, named Genotype Clustering. The results lead to two distinct conclusions, one practical and one more academic. From a practical perspective, the results suggest that, when suitably tuned, minimalist C. elegans-inspired foraging algorithms can lead to effective navigation to unknown targets even in the presence of repellents and under the influence of a significant sensor noise. From an academic perspective, the work demonstrates that even simple models can serve as an interesting and informative testbed for exploring fundamental evolutionary principles. The simulated robots were grounded in real hardware parameters, aiming at future application of the foraging algorithms in real robots. Another achievement of the project was the development of the simulation framework that provides a simple yet flexible program for the development and optimisation of behavioural algorithms