Comprehensive Characterization of Large Piezoresistive Variation of Ni-PDMS Composites

This work presents a comprehensive investigation of the piezoresistive response of a metal-polymer composite for robotic tactile sensor application. Composite samples, based on nickel nanostructured conductive filler in a polydimetihylsiloxane (PDMS) insulating elastomeric matrix, were prepared changing several process parameters like thickness, composition of the polymer and nickel filler content. A variation of electric resistance up to nine orders of magnitude under applied uniaxial load was measured in the fabricated samples. Cost efficient materials, simplicity of the process, large sensibility, and harsh environment compatibility make this quantum tunnelling composite adapted to be integrated as sensing coating in space robotic applications.

Emergence and development of embodied cognition: a constructivist approach using robots

A constructivist approach to cognition assumes the minimal and the simplest set of initial principles or mechanisms, embeds them in realistic circumstances, and lets the entire system evolve under close observation. This paper presents a line of research along this approach trying to connect embodiment to social cognition. First, we show that a mere physical body, when driven toward some task goal, provides a clear information structure, for action execution and perception. As a mechanism of autonomous exploration of such structure, "embodiment as a coupled chaotic field" is proposed, with experiments showing emergent and adaptive behavior. Scaling up the principles, a simulation of the fetal/neonatal motor development is presented. The musculo-skeletal system, basic nervous system, and the uterus environment are simulated. The neural-body dynamics exhibit spontaneous exploration of a variety of motor patterns. Lastly, a robotic experiment is presented to show that visual-motor self-learning can lead to neonatal imitation.

Early motor development from partially ordered neural-body dynamics: experiments with a cortico-spinal-musculo-skeletal model

Early human motor development has the nature of spontaneous exploration and boot-strap learning, leading to open-ended acquisition of versatile flexible motor skills. Since dexterous motor skills often exploit body-environment dynamics, we formulate the developmental principle as the spontaneous exploration of consistent dynamical patterns of the neural-body-environment system. We propose that partially ordered dynamical patterns emergent from chaotic oscillators coupled through embodiment serve as the core driving mechanism of such exploration. A model of neuro-musculo-skeletal system is constructed capturing essential features of biological systems. It consists of a skeleton, muscles, spindles, tendon organs, spinal circuits, medullar circuits (CPGs), and a basic cortical model. Through a series of experiments with a minimally simple body model, it is shown that the model has the capability of generating partially ordered behavior, a mixture of chaotic exploration and ordered entrained patterns. Models of self-organizing cortical areas for primary somatosensory and motor areas are introduced. They participate in the explorative learning by simultaneously learning and controlling the movement patterns. A scaled up version of the model, a human infant model, is constructed and put through preliminary experiments. Some meaningful motor behavior emerged including rolling over and crawling-like motion. The results show the possibility that a rich variety of meaningful behavior can be discovered and acquired by the neural-body dynamics without pre-defined coordinated control circuits.