Leandro Lorenzelli

Bio: Leandro Lorenzelli is an academic researcher from fondazione bruno kessler. The author has contributed to research in topics: Tactile sensor & Flexible electronics. The author has an hindex of 34, co-authored 162 publications receiving 4159 citations. Previous affiliations of Leandro Lorenzelli include University of Trento.

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.

Ultra-thin chips for high-performance flexible electronics

Abstract: Flexible electronics has significantly advanced over the last few years, as devices and circuits from nanoscale structures to printed thin films have started to appear. Simultaneously, the demand for high-performance electronics has also increased because flexible and compact integrated circuits are needed to obtain fully flexible electronic systems. It is challenging to obtain flexible and compact integrated circuits as the silicon based CMOS electronics, which is currently the industry standard for high-performance, is planar and the brittle nature of silicon makes bendability difficult. For this reason, the ultra-thin chips from silicon is gaining interest. This review provides an in-depth analysis of various approaches for obtaining ultra-thin chips from rigid silicon wafer. The comprehensive study presented here includes analysis of ultra-thin chips properties such as the electrical, thermal, optical and mechanical properties, stress modelling, and packaging techniques. The underpinning advances in areas such as sensing, computing, data storage, and energy have been discussed along with several emerging applications (e.g., wearable systems, m-Health, smart cities and Internet of Things etc.) they will enable. This paper is targeted to the readers working in the field of integrated circuits on thin and bendable silicon; but it can be of broad interest to everyone working in the field of flexible electronics.

Flexible Tactile Sensors Using Screen-Printed P(VDF-TrFE) and MWCNT/PDMS Composites

Abstract: This paper presents and compares two different types of screen-printed flexible and conformable pressure sensors arrays In both variants, the flexible pressure sensors are in the form of segmental arrays of parallel plate structure—sandwiching the piezoelectric polymer polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] between two printed metal layers of silver (Ag) in one case and the piezoresistive [multiwall carbon nanotube (MWCNT) mixed with poly(dimethylsiloxane (PDMS)] layer in the other Each sensor module consists of $4 \times 4$ sensors array with 1-mm $\times 1$ -mm sensitive area of each sensor The screen-printed piezoelectric sensors array exploits the change in polarization level of P(VDF-TrFE) to detect dynamic tactile parameter such as contact force Similarly, the piezoresistive sensors array exploits the change in resistance of the bulk printed layer of MWCNT/PDMS composite The two variants are compared on the basis of fabrication by printing on plastic substrate, ease of processing and handling of the materials, compatibility of the dissimilar materials in multilayers structure, adhesion, and finally according to the response to the normal compressive forces The foldable pressure sensors arrays are completely realized using screen-printing technology and are targeted toward realizing low-cost electronic skin

Piezoelectric oxide semiconductor field effect transistor touch sensing devices

Abstract: This work presents piezoelectric oxide semiconductor field effect transistor (POSFET) based touch sensing devices. These devices are fabricated by spin coating thin (∼2.5 μm) piezoelectric polymer film directly on to the gate area of metal oxide semiconductor (MOS) transistor. The polymer film is processed in situ and challenging issues such as in situ poling of piezoelectric polymer film, without damaging or altering the characteristics of underlying MOS devices, are successfully dealt with. The POSFET device represents an integral “sensotronic” unit comprising of transducer and the transistor—thereby sensing as well as conditioning (and processing) the touch signal at “same site.”

Pursuing prosthetic electronic skin.

Abstract: Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

Tactile Sensing—From Humans to Humanoids

Abstract: Starting from human ?sense of touch,? this paper reviews the state of tactile sensing in robotics. The physiology, coding, and transferring tactile data and perceptual importance of the ?sense of touch? in humans are discussed. Following this, a number of design hints derived for robotic tactile sensing are presented. Various technologies and transduction methods used to improve the touch sense capability of robots are presented. Tactile sensing, focused to fingertips and hands until past decade or so, has now been extended to whole body, even though many issues remain open. Trend and methods to develop tactile sensing arrays for various body sites are presented. Finally, various system issues that keep tactile sensing away from widespread utility are discussed.

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.

Advanced Thermoelectric Design: From Materials and Structures to Devices

Abstract: The long-standing popularity of thermoelectric materials has contributed to the creation of various thermoelectric devices and stimulated the development of strategies to improve their thermoelectric performance. In this review, we aim to comprehensively summarize the state-of-the-art strategies for the realization of high-performance thermoelectric materials and devices by establishing the links between synthesis, structural characteristics, properties, underlying chemistry and physics, including structural design (point defects, dislocations, interfaces, inclusions, and pores), multidimensional design (quantum dots/wires, nanoparticles, nanowires, nano- or microbelts, few-layered nanosheets, nano- or microplates, thin films, single crystals, and polycrystalline bulks), and advanced device design (thermoelectric modules, miniature generators and coolers, and flexible thermoelectric generators). The outline of each strategy starts with a concise presentation of their fundamentals and carefully selected examples. In the end, we point out the controversies, challenges, and outlooks toward the future development of thermoelectric materials and devices. Overall, this review will serve to help materials scientists, chemists, and physicists, particularly students and young researchers, in selecting suitable strategies for the improvement of thermoelectrics and potentially other relevant energy conversion technologies.