Leonardo Barboni

Bio: Leonardo Barboni is an academic researcher from University of the Republic. The author has contributed to research in topics: Wireless sensor network & Key distribution in wireless sensor networks. The author has an hindex of 7, co-authored 24 publications receiving 319 citations. Previous affiliations of Leonardo Barboni include University of Genoa & University of Geneva.

Towards Tactile Sensing System on Chip for Robotic Applications

Abstract: This paper presents the research on tactile sensing system on chip. The tactile sensing chips comprise of 5 × 5 array of Piezoelectric Oxide Semiconductor Field Effect Transistor (POSFET) devices and temperature sensors. The POSFET devices are obtained by spin coating piezoelectric polymer, poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), films directly on to the gate area of Metal Oxide Semiconductor (MOS) transistors. The tactile sensing chips are able to measure dynamic contact forces and temperatures. The readout and the data acquisition system to acquire the tactile signals are also presented. The chips have been extensively tested over wide range of dynamic contact forces and temperatures and the experimental results are presented. The paper also reports the research on tactile sensing chips with POSFET array and the integrated electronics.

TFET-Based Circuit Design Using the Transconductance Generation Efficiency $ {g}_{m}/ {I}_{d}$ Method

Abstract: Tunnel field effect transistors (TFETs) have emerged as one of the most promising post-CMOS transistor technologies. In this paper, we: 1) review the perspectives of such devices for low-power high-frequency analog integrated circuit applications (e.g., GHz operation with sub-0.1 mW power consumption); 2) discuss and employ a compact TFET device model in the context of the $g_{m}/I_{d}$ integrated analog circuit design methodology; and 3) compare several proposed TFET technologies for such applications. The advantages of TFETs arise since these devices can operate in the sub-threshold region with larger transconductance-to-current ratio than traditional FETs, which is due to the current turn-on mechanism being interband tunneling rather than thermionic emission. Starting from technology computer-aided design and/or analytical models for Si-FinFETs, graphene nano-ribbon (GNR) TFETs and InAs/GaSb TFETs at the 15-nm gate-length node, as well as InAs double-gate TFETs at the 20-nm gate-length node, we conclude that GNR TFETs might promise larger bandwidths at low-voltage drives due to their high current densities in the sub-threshold region. Based on this analysis and on theoretically predicted properties, GNR TFETs are identified as one of the most attractive field effect transistor technologies proposed-to-date for ultra-low power analog applications.

Evaluating Energy Consumption in Wireless Sensor Networks Applications

Abstract: Wireless sensor networks (WSNs) simulation is essential for the development and optimization of such kind of networks. In this paper we present modifications made to prowler, a WSNs simulator, making its MAC protocol model compliant with the crossbow MICAz mote running on Tiny OS. Moreover, we added radio propagation models to the simulator and, most important, we implemented an energy consumption estimation model of the CC2420 radio chip. Then, the simulator is addressed to the development of WSNs applications with a particular emphasis on energy consumption optimization (and consequently battery lifetime). We present as case study the comparison between simulated results of two different physical deployments, showing how real operating conditions can affect and modify the system behavior in comparison with the results predicted by theoretical analysis.

Experimental Analysis of Wireless Sensor Nodes Current Consumption

Abstract: Wireless sensor node (WSN) lifetime is correlated with the battery current usage profile. State of the art in wireless sensor nodes current consumption shows that available models have not been extensively tested and experimentally validated. This work aims to seek answers to the following questions: is it accurate the node lifetime prediction obtained with available models? Moreover, is the radio transceiver always responsible for depleting the battery? In order to perform experimental evaluations, we implemented a prototype board that enables to visualize charge extracted from batteries and battery current consumption waveforms of wireless sensor nodes. We selected benchmarks that represent usual tasks in WSN applications and we made experimental evaluations of battery current consumption. Finally, a battery full-depletion time measurement has been performed. Overall results are presented and discussed.

Perspectives of TFETs for low power analog ICs

Abstract: In this paper we show that tunnel field effect transistors (TFETs) biased in the subthreshold region promise several advantages for low-power/high-frequency analog IC applications (e.g. GHz operation with sub-0.1 mW power consumption). Analytical and TCAD models for graphene nano-ribbon (GNR) and InAs/GaSb nanowire TFETs are employed, respectively, for the first time in subthreshold analog circuit examples using the g m /I d integrated circuit (IC) design technique. From comparison of these TFET technologies with traditional FETs it is observed that due to the higher currents per unit gate width at low voltage for TFETs, smaller, higher speed, and lower power analog circuits are enabled.

Technologies for Printing Sensors and Electronics Over Large Flexible Substrates: A Review

Abstract: Printing sensors and electronics over flexible substrates are an area of significant interest due to low-cost fabrication and possibility of obtaining multifunctional electronics over large areas. Over the years, a number of printing technologies have been developed to pattern a wide range of electronic materials on diverse substrates. As further expansion of printed technologies is expected in future for sensors and electronics, it is opportune to review the common features, the complementarities, and the challenges associated with various printing technologies. This paper presents a comprehensive review of various printing technologies, commonly used substrates and electronic materials. Various solution/dry printing and contact/noncontact printing technologies have been assessed on the basis of technological, materials, and process-related developments in the field. Critical challenges in various printing techniques and potential research directions have been highlighted. Possibilities of merging various printing methodologies have been explored to extend the lab developed standalone systems to high-speed roll-to-roll production lines for system level integration.

A review of piezoelectric polymers as functional materials for electromechanical transducers

Abstract: Polymer based MEMS and microfluidic devices have the advantages of mechanical flexibility, lower fabrication cost and faster processing over silicon based ones. Also, many polymer materials are considered biocompatible and can be used in biological applications. A valuable class of polymers for microfabricated devices is piezoelectric functional polymers. In addition to the normal advantages of polymers, piezoelectric polymers can be directly used as an active material in different transduction applications. This paper gives an overview of piezoelectric polymers based on their operating principle. This includes three main categories: bulk piezoelectric polymers, piezocomposites and voided charged polymers. State-of-the-art piezopolymers of each category are presented with a focus on fabrication techniques and material properties. A comparison between the different piezoelectric polymers and common inorganic piezoelectric materials (PZT, ZnO, AlN and PMN?PT) is also provided in terms of piezoelectric properties. The use of piezopolymers in different electromechanical devices is also presented. This includes tactile sensors, energy harvesters, acoustic transducers and inertial sensors.

Directions Toward Effective Utilization of Tactile Skin: A Review

Abstract: A wide variety of tactile (touch) sensors exist today for robotics and related applications. They make use of various transduction methods, smart materials and engineered structures, complex electronics, and sophisticated data processing. While highly useful in themselves, effective utilization of tactile sensors in robotics applications has been slow to come and largely remains elusive today. This paper surveys the state of the art and the research issues in this area, with the emphasis on effective utilization of tactile sensors in robotic systems. One specific with the use of tactile sensing in robotics is that the sensors have to be spread along the robot body, the way the human skin is-thus dictating varied 3-D spatio-temporal requirements, decentralized and distributed control, and handling of multiple simultaneous tactile contacts. Satisfying these requirements pose challenges to making tactile sensor modality a reality. Overcoming these challenges requires dealing with issues such as sensors placement, electronic/mechanical hardware, methods to access and acquire signals, automatic calibration techniques, and algorithms to process and interpret sensing data in real time. We survey this field from a system perspective, recognizing the fact that the system performance tends to depend on how its various components are put together. It is hoped that the survey will be of use to practitioners designing tactile sensing hardware (whole-body or large-patch sensor coverage), and to researchers working on cognitive robotics involving tactile sensing.

Energy replenishment using renewable and traditional energy resources for sustainable wireless sensor networks: A review

Abstract: In recent years there has been several technological advances in Wireless Sensor Networks (WSN), but energy still remains a paramount resource. The amount of available energy has a direct effect on the performance, functionality and lifetime of WSN. Being bound by cost and size, sensor nodes are usually equipped with limited amount of energy and therefore requires a replacement of batteries occasionally. But replacement might not always be feasible option and in some scenarios might even be prohibitive. This indicates the need for more viable solutions, these involve generating energy at the sensor nodes or have it delivered to them i.e., energy harvesting or wireless energy transfer. The objective of this paper is threefold: first we present a survey on potential renewable energy resources along with their characteristics and applications in WSN. Second, this study also describes various battery recharging techniques and their applications with respect to WSN. Finally, we discuss formidable issues, challenges and future research directions.