Unique elastomeric rotary actuators based on pneumatically driven peristaltic motion are demonstrated. Using silicone-based wheels, these motors enable a new class of soft locomotion not found in nature, which is capable of withstanding impact, traversing irregular terrain, and operating in water. For soft robotics, this work marks progress toward providing torque without bending actuators.
This work describes disposable plasma generators made from metallized paper. The fabricated plasma generators with layered and patterned sheets of paper provide a simple and flexible format for dielectric barrier discharge to create atmospheric plasma without an applied vacuum. The porosity of paper allows gas to permeate its bulk volume and fuel plasma, while plasma-induced forced convection cools the substrate. When electrically driven with oscillating peak-to-peak potentials of ±1 to ±10 kV, the paper-based devices produced both volume and surface plasmas capable of killing microbes. The plasma sanitizers deactivated greater than 99% of Saccharomyces cerevisiae and greater than 99.9% of Escherichia coli cells with 30 s of noncontact treatment. Characterization of plasma generated from the sanitizers revealed a detectable level of UV-C (1.9 nW·cm), modest surface temperature (60°C with 60 s of activation), and a high level of ozone (13 ppm with 60 s of activation). These results deliver insights into the mechanisms and suitability of paper-based substrates for active antimicrobial sanitization with scalable, flexible sheets. In addition, this work shows how paper-based generators are conformable to curved surfaces, appropriate for kirigami-like "stretchy" structures, compatible with user interfaces, and suitable for sanitization of microbes aerosolized onto a surface. In general, these disposable plasma generators represent progress toward biodegradable devices based on flexible renewable materials, which may impact the future design of protective garments, skin-like sensors for robots or prosthetics, and user interfaces in contaminated environments.paper-based electronics | plasma | touch sensors | kirigami | sanitization
Enabling the paradigm of quality by design requires the ability to quantitatively correlate material properties and process variables to measureable product performance attributes. Conventional, quality-by-test methods for determining tablet breaking force and disintegration time usually involve destructive tests, which consume significant amount of time and labor and provide limited information. Recent advances in material characterization, statistical analysis, and machine learning have provided multiple tools that have the potential to develop nondestructive, fast, and accurate approaches in drug product development. In this work, a methodology to predict the breaking force and disintegration time of tablet formulations using nondestructive ultrasonics and machine learning tools was developed. The input variables to the model include intrinsic properties of formulation and extrinsic process variables influencing the tablet during manufacturing. The model has been applied to predict breaking force and disintegration time using small quantities of active pharmaceutical ingredient and prototype formulation designs. The novel approach presented is a step forward toward rational design of a robust drug product based on insight into the performance of common materials during formulation and process development. It may also help expedite drug product development timeline and reduce active pharmaceutical ingredient usage while improving efficiency of the overall process.
This article describes a process of fabricating highly porous paper from cellulosic fibers and carbon black (CB) with tunable conductivity. By embossing such paper, its porosity decreases while its conductivity increases. Tuning the porosity of composite paper alters the magnitude and trend of conductivity over a spectrum of concentrations of conductive particles. The largest increase in conductivity from 8.38 × 10–6 to 2.5 × 10–3 S/m by a factor of ∼300 occurred at a percolation threshold of 3.8 wt % (or 0.36 vol %) with the composite paper plastically compressed by 410 MPa, which caused a decrease of porosity from 88% to 42% on average. Our composite paper showed stable piezoresistive responses within a broad pressure range from 1 kPa up to 5.5 MPa for 800 cycles. The piezoresistive sensitivities of the composite paper were dependent on concentration and decreased with pressure. Composite paper with 7.5 wt % CB had sensitivities of −0.514 kPa–1 over applied pressures ranging from 1 to 50 kPa and −0.215 kPa–1 from 1 to 250 kPa. This piezoresistive paper with embossed patterns enabled touch sensing and detection of damage from darts and punches. Understanding the percolation behavior of three-phase composites (cellulosic fibers/conductive particles/air) and their response to damage, pressure, and processing conditions has the potential to enable scalable applications in prosthetics and robotics, haptic feedback, or structural health monitoring on expansive surfaces of buildings and vehicles.
user interface. In other words, increasing resolution or adding sites for the detection of touch, generally requires augmenting the number of interconnects. With the exception of using a single electrode-based sensing technique to make natural and inanimate objects become user interfaces, there has been a lack of effort in the reduction of the number of wired leads required for scalable sensing of touch. [9] In contrast to electronic touch sensors, skin on humans/vertebrates uses hierarchical neural networks to transmit the relative spatial detection and intensity of force on fleshy surfaces to the brain. [10] These neural networks do not depend on having a pair of running wires for each location. Instead, they have developed mechanisms for sending spatial information about touch along the spinal cord. Inspired by this concept, Tee et al. presented a skininspired organic digital mechanoreceptor, which converted force-based stimuli into digital signals with varied frequencies to mimic the communication between biological mechanoreceptors and the brain. [11] Similarly, there are opportunities to build electrical networks to reduce the number of wired leads required for spatial detection of touch on synthetic electronic skins.The advancements in skin-like sensing with flexible electronics have moved toward the design and fabrication of active electronic components arrayed on flexible sheets with surface areas less than 10 cm in diameter. [12][13][14][15][16] For example, Someya and co-workers demonstrated an application of thin-film transistors in skin-like sensors capable of measuring distributed pressures over a 9 cm × 9 cm footprint. [12] The size of the sensors is typically dependent on the method of fabrication, and current skin-like sensors often cover small areas (i.e., much less area than that of human skin) because of the limited size of semiconductor-based wafers. As mentioned previously, the number of wired leads in conventional arrays of skin-like sensors increases with the square root of the number of buttons. While this scaling may appear favorable, there are still difficulties with making large sensing grids, as a larger quantity of traces requires more space for wired connections and multiplexed measurements.In this work, we present an approach to passive sensing for skin-like sensors consisting of tunable resistive networks and This work presents a unique approach to the design, fabrication, and characterization of paper-based, skin-like sensors that use patterned resistive networks for passive, scalable sensing with a reduced number of interconnects. When touched or wetted with water, the sensors in the resistive networks detect significant changes in electrical impedance. Fabricating these resistive networks and sensors in a single sheet of metallized paper reduces the number of distinct inputs/outputs to the arrayed sensors. For human-electrode interactions, circuit-based models guide the design/material processing of the resistive networks and selection of operating frequencies-typically ranging...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.