Beveled microneedles with channel for transdermal injection and sampling, fabricated with minimal steps and standard MEMS technology.

Microneedles hold the potential for enabling shallow skin penetration applications where biomarkers are extracted from the interstitial fluid (ISF) and drugs are injected in a painless and effective manner. To this purpose, needles must have an inner channel. Channeled needles were demonstrated using custom silicon microtechnology, having several needle tip geometries.

Applications of Chipless RFID Humidity Sensors to Smart Packaging Solutions.

Packaging solutions have recently evolved to become smart and intelligent thanks to technologies such as RFID tracking and communication systems, but the integration of sensing functionality in these systems is still under active development. In this paper, chipless RFID humidity sensors suitable for smart packaging are proposed together with a novel strategy to tune their performances and their operating range. The sensors are flexible, fast, low-cost and easy to fabricate and can be read wirelessly.

A Fingertip-Mimicking 12×16 200μm-Resolution e-skin Taxel Readout Chip with per-Taxel Spiking Readout and Embedded Receptive Field Processing.

This paper presents an electronic skin (e-skin) taxel array readout chip in 0.18μm CMOS technology, achieving the highest reported spatial resolution of 200μm, comparable to human fingertips. A key innovation is the integration on chip of a 12×16 polyvinylidene fluoride (PVDF)-based piezoelectric sensor array with per-taxel signal conditioning frontend and spiking readout combined with local embedded neuromorphic first-order processing through Complex Receptive Fields (CRFs).

Enhancing the Deposition Rate and Uniformity in 3D Gold Microelectrode Arrays via Ultrasonic-Enhanced Template-Assisted Electrodeposition.

In the pursuit of refining the fabrication of three-dimensional (3D) microelectrode arrays (MEAs), this study investigates the application of ultrasonic vibrations in template-assisted electrodeposition. This was driven by the need to overcome limitations in the deposition rate and the height uniformity of microstructures developed using conventional electrodeposition methods, particularly in the field of in vitro electrophysiological investigations. This study employs a template-assisted electrodeposition approach coupled with ultrasonic vibrations to enhance the deposition process.

Temperature Dependence of Photoluminescence Intensity and Spin Contrast in Nitrogen-Vacancy Centers.

We report on measurements of the photoluminescence properties of single nitrogen-vacancy centers in diamond at temperatures between 4 K and 300 K. We observe a strong reduction of the PL intensity and spin contrast between ca. 10 K and 100 K that recovers to high levels below and above.

Part II: Impedance-based DNA biosensor for detection of isolated strains of phytopathogen Ralstonia solanacearum.

In Part I, we demonstrated the complete development of a label-free, ultra-low sample volume requiring DNA-based biosensor to detect Ralstonia solanacearum, an aerobic non-spore-forming, Gram-negative, plant pathogenic bacterium, using non-faradaic electrochemical impedance spectroscopy (nf-EIS). We also presented the sensor's sensitivity, specificity, and electrochemical stability. In this article, we highlight the specificity study of the developed DNA-based impedimetric biosensor to detect various strains of R.

Tailoring the Performance of a Nafion 117 Humidity Chipless RFID Sensor: The Choice of the Substrate.

Chipless radio-frequency identification (RFID) sensors are not yet widespread in practical applications because of their limited sensitivity and selectivity when compared to more mature sensing technologies. The search for a suitable material to perform the sensing function has often been focused on the most common materials used in electrochemical sensing approaches, but little work has been done to directly relate the performances of chipless or microwave sensors to the characteristics of the materials used to fabricate them. In this work we are simulating the impact of the substrate material on the performances of a chipless RFID sensor for humidity detection.

Part I: Non-faradaic electrochemical impedance-based DNA biosensor for detecting phytopathogen - Ralstonia solanacearum.

Herein, we report for the first time the development of a label-free, non-faradaic, and highly sensitive DNA-based impedimetric sensor using micro-sized gold interdigitated electrodes (IDE) to detect a soil-borne agricultural pathogen Ralstonia solanacearum. A universal 30 oligomer single-stranded DNA (ssDNA) probe lpxC4 having specificity towards R. solanacearum is successfully immobilized on the surface of IDE along with mercaptohexanol.

A review of recent advances in plant-pathogen detection systems.

Worldwide, a substantial economic loss in agricultural products is caused by plant pathogens. The increased losses in agriculture have drawn attention towards the development of miniaturized pathogen detection systems for phytopathology. This review paper's main selling point supports recent research (from 2015 to 2022) and technological advancements in the field of plant pathogen detection.

Plant pathogenicity and associated/related detection systems. A review.

There is an increasing demand for the development of various tools for diagnosis and control of plant infections. The early diagnosis of plant disease serves as a vital element to improve crop productivity and meet demands of the ever-growing world population. The traditional methods of plant disease detection are time consuming, laborious and require 3-5 days to estimate the disease incidence.

Surgical tracheotomy in COVID-19 patients: an Italian single centre experience.

Purpose: Coronavirus infection disease 2019 (COVID-19) causes in 10% of patients a severe respiratory distress syndrome managed with invasive mechanical ventilation (IMV), sometimes difficult to wean. The role of tracheotomy is debated for the possible risks for patients and staff. We are going to describe here our experience with surgical tracheotomy in COVID-19 positive patients.

Micropatterning of Substrates for the Culture of Cell Networks by Stencil-Assisted Additive Nanofabrication.

The fabrication of in vitro neuronal cell networks where cells are chemically or electrically connected to form functional circuits with useful properties is of great interest. Standard cell culture substrates provide ensembles of cells that scarcely reproduce physiological structures since their spatial organization and connectivity cannot be controlled. Supersonic Cluster Beam Deposition (SCBD) has been used as an effective additive method for the large-scale fabrication of interfaces with extracellular matrix-mimicking surface nanotopography and reproducible morphological properties for cell culture.

Prototyping a memristive-based device to analyze neuronal excitability.

Many efforts have been spent in the last decade for the development of nanoscale synaptic devices integrated into neuromorphic circuits, trying to emulate the behavior of natural synapses. The study of brain properties with the standard approaches based on biocompatible electrodes coupled to conventional electronics, however, presents strong limitations, which in turn could be overcame by the in-situ growth of neuronal networks coupled to memristive devices. To meet this challenging task, here two different chips were designed and fabricated for culturing neuronal cells and sensing their electrophysiological activity.

Stretchable wireless system for sweat pH monitoring.

Sensor-laden wearable systems that are capable of providing continuous measurement of key physiological parameters coupled with data storage, drug delivery and feedback therapy have attracted huge interest. Here we report a stretchable wireless system for sweat pH monitoring, which is able to withstand up to 53% uniaxial strain and more than 500 cycles to 30% strain. The stretchability of the pH sensor patch is provided by a pair of serpentine-shaped stretchable interconnects.

Nanoscale Imaging of Current Density with a Single-Spin Magnetometer.

Charge transport in nanostructures and thin films is fundamental to many phenomena and processes in science and technology, ranging from quantum effects and electronic correlations in mesoscopic physics, to integrated charge- or spin-based electronic circuits, to photoactive layers in energy research. Direct visualization of the charge flow in such structures is challenging due to their nanometer size and the itinerant nature of currents. In this work, we demonstrate noninvasive magnetic imaging of current density in two-dimensional conductor networks including metallic nanowires and carbon nanotubes.

Local dynamics of topological magnetic defects in the itinerant helimagnet FeGe.

Chiral magnetic interactions induce complex spin textures including helical and conical spin spirals, as well as particle-like objects such as magnetic skyrmions and merons. These spin textures are the basis for innovative device paradigms and give rise to exotic topological phenomena, thus being of interest for both applied and fundamental sciences. Present key questions address the dynamics of the spin system and emergent topological defects.

An unconventional approach to impedance microbiology: detection of culture media conductivity variations due to bacteriophage generated lyses of host bacteria.

A novel and unconventional approach to impedance microbiology has been under investigation. In our approach, solution conductivity variations are generated from bacteriophage lyses of infected host cells and the consequent release of conductive endoplasmic material. To sensitively detect the lysis, low conductive growth media have been developed.

Recent sensing technologies for pathogen detection in milk: a review.

Quality control utilising Hazard Analysis and Critical Control Points in the dairy industry generates a large volume of samples. The associated costs are significant. The development and application of fast, sensitive and cost effective analytical systems for pathogen detection in milk could aid the industry in the reduction of overheads, find new uses in dairy farming and production precision management and unlock new markets.

PDMS/Kapton interface plasma treatment effects on the polymeric package for a wearable thermoelectric generator.

The present work highlights the progress in the field of polymeric package reliability engineering for a flexible thermoelectric generator realized by thin-film technology on a Kapton substrate. The effects of different plasma treatments on the mechanical performance at the interface of a poly(dimethylsiloxane) (PDMS)/Kapton assembly were investigated. To increase the package mechanical stability of the realized wearable power source, the Kapton surface wettability after plasma exposure was investigated by static contact-angle measurements using deionized water and PDMS as test liquids.

Long-term outdoor reliability assessment of a wireless unit for air-quality monitoring based on nanostructured films integrated on micromachined platforms.

We have fabricated and tested in long-term field operating conditions a wireless unit for outdoor air quality monitoring. The unit is equipped with two multiparametric sensors, one miniaturized thermo-hygrometer, front-end analogical and digital electronics, and an IEEE 802.15.

Development of an integrated electrochemical system for in vitro yeast viability testing.

This work describes the development and testing of a microfabricated sensor for rapid cell growth monitoring, especially focused on yeast quality assessment for wine applications. The device consists of a NMOS ISFET sensor with Si(3)N(4) gate, able to indirectly monitor extracellular metabolism through pH variation of the medium, and a solid-state reference electrode implemented with PVC membranes doped with lipophilic salts (tetrabutylammonium-tetrabutylborate (TBA-TBB) and Potassium tetrakis(4-chlorphenyl)borate (KTClpB)). The use of a solid state reference electrode enables the implementation of a large number of cell assays in parallel, without the need of external conventional reference electrodes.

Mechanical characterization of thin TiO2 films by means of microelectromechanical systems-based cantilevers.

The measurement of mechanical parameters by means of microcantilever structures offers a reliable and accurate alternative to traditional methods, especially when dealing with thin films, which are extensively used in microfabrication technology and nanotechnology. In this work, microelectromechanical systems (MEMS)-based piezoresistive cantilevers were realized and used for the determination of Young's modulus and residual stress of thin titanium dioxide (TiO(2)) deposited by sputtering from a TiO(2) target using a rf plasma discharge. Films were deposited at different thicknesses, ranging from a few to a hundred nanometers.

Developing a genomic-based point-of-care diagnostic system for rheumatoid arthritis and multiple sclerosis.

In this paper the methodology of designing a genomic-based point-of-care diagnostic system composed of a microfluidic Lab-On-Chip, algorithms for microarray image information extraction and knowledge modeling of clinico-genomic patient data is presented. The data are processed by genome wide association studies for two complex diseases: rheumatoid arthritis and multiple sclerosis. Respecting current technological limitations of autonomous molecular-based Lab-On-Chip systems the approach proposed in this work aims to enhance the diagnostic accuracy of the miniaturized LOC system.

SPICE model for lossy piezoelectric polymers.

This work presents the transmission line equivalent model for lossy piezoelectric polymers and its SPICE implementation. The model includes the mechanical/viscoelastic, dielectric/electrical, and piezoelectric/electromechanical losses in a novel way by using complex elastic, dielectric, and piezoelectric constants obtained from the measured impedances of PVDF and PVDF-TrFE samples by nonlinear regression technique. The equivalent circuit parameters are derived from analogies between a lossy electrical transmission line and acoustic wave propagation.

Space and time-resolved gene expression experiments on cultured mammalian cells by a single-cell electroporation microarray.

Single-cell experiments represent the next frontier for biochemical and gene expression research. Although bulk-scale methods averaging populations of cells have been traditionally used to investigate cellular behavior, they mask individual cell features and can lead to misleading or insufficient biological results. We report on a single-cell electroporation microarray enabling the transfection of pre-selected individual cells at different sites within the same culture (space-resolved), at arbitrarily chosen time points and even sequentially to the same cells (time-resolved).