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In recent years, the issue of electronic waste production has gained significant attention. To mitigate the environmental impact of e-waste, one approach under consideration involves the development of biodegradable electronic devices or devices that dissolve in the environment at the end of their life cycle. This study presents results related to the creation of a sensor that effectively addresses both criteria. The device was constructed using a composite material formed by impregnating a pullulan membrane (a biodegradable water-soluble biopolymer) with 1-Ethyl-3-Methylimidazolium tetrafluoroborate (a water-soluble ionic liquid) and coating the product with a conductive silver-based varnish. Capitalizing on the piezoionic effect, the device has demonstrated functionality as a vibration sensor with a sensitivity of approximately 5.5 × 10−5 V/mm and a resolution of about 1 mm. The novelty of this study lies in the unique combination of materials. Unlike the use of piezoelectric materials, this combination allows for the production of a device that does not require an external potential difference generator to function properly as a sensor. Furthermore, the combination of a biopolymer, such as pullulan, and an ionic liquid, both readily soluble in water, in creating an active electronic component represents an innovation in the field of vibration sensors. [ABSTRACT FROM AUTHOR]

In recent years, the issue related to electronic waste production has been gaining prominence. One of the approaches considered to limit the impact of e-waste on the environment involves the development of biodegradable electronic devices or devices that dissolve in the environment at the end of their life cycle. In this study, we present the preliminary results related to the creation of a sensor that could meet both criteria. The device was constructed using a composite material obtained by impregnating a membrane of polycaprolactone (a biodegradable polymer) with 1-Ethyl-3-Methylimidazolium tetrafluoroborate (a water-soluble ionic liquid), which was coated with a conductive silver-based varnish. Leveraging the piezoionic effect, the device has been proven to function as a vibration sensor with a sensitivity of approximately 1.9 × 10−5 V/mm and a resolution of about 0.15 mm. [ABSTRACT FROM AUTHOR]

Bio-derived polymers are promising materials for the development of eco-friendly sensors. Composites, composed of bacterial cellulose sheets sandwiched between two layers of conducting polymers and infused with ionic liquids, exhibit generating properties when utilized as deformation sensors. The composite material underwent a frequency analysis to explore the relationship between the transduction property and the frequency of the applied mechanical deformation. A model identification was performed using the acquired experimental data. The linearity of the system was examined, and the findings show that a second-order system, adequately approximates the system's dynamics. [ABSTRACT FROM AUTHOR]

This paper presents an innovative wormlike robot controlled by cellular neural networks (CNNs) and made of an ionic polymer-metal composite (IPMC) self-actuated skeleton. The IPMC actuators, from which it is made of, are new materials that behave similarly to biological muscles. The idea that inspired the work is the possibility of using IPMCs to design autonomous moving structures. CNNs have already demonstrated their powerfulness as new structures for bio-inspired locomotion generation and control. The control scheme for the proposed IPMC moving structure is based on CNNs. The wormlike robot is totally made of IPMCs, and each actuator has to carry its own weight. All the actuators are connected together without using any other additional part, thereby constituting the robot structure itself. Worm locomotion is performed by bending the actuators sequentially from "tail" to "head," imitating the traveling wave observed in real-world undulatory locomotion. The activation signals are generated by a CNN. In the authors' opinion, the proposed strategy represents a promising solution in the field of autonomous and light structures that are capable of reconfiguring and moving in line with spatial-temporal dynamics generated by CNNs. Index Terms--Cellular neural networks (CNNs), smart actuators, undulatory locomotion, wormlike robot.

The electrical behavior of an ionic polymer-metal composite (IPMC), when a voltage is applied across its thickness, is investigated. IPMCs are new materials of increasing interest, to implement artificial muscles in robotic applications, and to implement displacement sensors in measurement fields. They are particularly light and they deform if electrically stimulated with a very low voltage; on the other hand they produce a voltage if mechanically bent. An understanding of the phenomena involved in electromechanical energy conversion may address research activity toward the building of innovative devices where both sensing and actuating functions could be integrated in the same material. The paper illustrates a model that describes the electrical behavior of an IPMC as an actuator using an equivalent circuit. It is a totally new nonlinear lumped parameter model which is able to describe all the phenomena observed in the flow of electrical current through the material, including nonlinear phenomena. The model has been validated by a large set of comparisons between simulations and experimental data. In all the cases analyzed the simulations agree with the experimental data. Index Terms--Actuators, electrical model, ionic polymer-metal composite (IPMC), nonlinear lumped parameter circuit.