Origami-inspired thin-film shape memory alloy devices.
Ontology highlight
ABSTRACT:
SUBMITTER: Velvaluri P
PROVIDER: S-EPMC8155017 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Soft, worm-like robots show promise in complex and constrained environments due to their robust, yet simple movement patterns. Although many such robots have been developed, they either rely on tethered power supplies and complex designs or cannot move external loads. To address these issues, we here introduce a novel, maggot-inspired, magnetically driven "mag-bot" that utilizes shape memory alloy-induced, thermoresponsive actuation and surface pattern-induced anisotropic friction to achieve locomotion inspired by fly larvae. This simple, untethered design can carry cargo that weighs up to three times its own weight with only a 17% reduction in speed over unloaded conditions thereby demonstrating, for the first time, how soft, untethered robots may be used to carry loads in controlled environments. Given their small scale and low cost, we expect that these mag-bots may be used in remote, confined spaces for small objects handling or as components in more complex designs.
| S-EPMC9300706 | biostudies-literature
Project description: Not available
| S-EPMC11344043 | biostudies-literature
Project description:Micro-/nanomechanical resonators are often used in material science to measure the elastic properties of ultrathin films or mass spectrometry to estimate the mass of various chemical and biological molecules. Measurements with these sensors utilize changes in the resonant frequency of the resonator exposed to an investigated quantity. Their sensitivities are, therefore, determined by the resonant frequency. The higher resonant frequency and, correspondingly, higher quality factor (Q-factor) yield higher sensitivity. In solution, the resonant frequency (Q-factor) decreases causing a significant lowering of the achievable sensitivity. Hence, the nanomechanical resonator-based sensors mainly operate in a vacuum. Identification by nanomechanical resonator also requires an additional reference measurement on the identical unloaded resonator making experiments, due to limiting achievable accuracies in current nanofabrication processes, yet challenging. In addition, the mass spectrometry by nanomechanical resonator can be routinely performed for light analytes (i.e., analyte is modelled as a point particle). For heavy analytes such as bacteria clumps neglecting their stiffness result in a significant underestimation of determined mass values. In this work, we demonstrate the extraordinary capability of hybrid shape memory alloy (SMA)-based nanomechanical resonators to i) notably tune the resonant frequencies and improve Q-factor of the resonator immersed in fluid, ii) determine the Young's (shear) modulus of prepared ultrathin film only from frequency response of the resonator with sputtered film, and iii) perform heavy analyte mass spectrometry by monitoring shift in frequency of just a single vibrational mode. The procedures required to estimate the Young's (shear) modulus of ultrathin film and the heavy analyte mass from observed changes in the resonant frequency caused by a phase transformation in SMA are developed and, afterward, validated using numerical simulations. The present results demonstrate the outstanding potential and capability of high frequency operating hybrid SMA-based nanomechanical resonators in sensing applications that can be rarely achieved by current nanomechanical resonator-based sensors.
| S-EPMC6862155 | biostudies-literature
Project description:Shape memory alloys are typical temperature-sensitive metallic functional materials due to superelasticity and shape recovery characteristics. The conventional shape memory effect involves the formation and deformation of thermally induced martensite and its reverse transformation. The shape recovery process usually takes place over a temperature range, showing relatively low temperature-sensitivity. Here we report novel Cu-Al-Fe-Mn shape memory alloys. Their stress-strain and shape recovery behaviors are clearly different from the conventional shape memory alloys. In this study, although the Cu-12.2Al-4.3Fe-6.6Mn and Cu-12.9Al-3.8Fe-5.6Mn alloys possess predominantly L2(1) parent before deformation, the 2H martensite stress-induced from L2(1) parent could be retained after unloading. Furthermore, their shape recovery response is extremely temperature-sensitive, in which a giant residual strain of about 9% recovers instantly and completely during heating. At the same time, the phenomenon of the jumping of the sample occurs. It is originated from the instantaneous completion of the reverse transformation of the stabilized 2H martensite. This novel Cu-Al-Fe-Mn shape memory alloys have great potentials as new temperature-sensitive functional materials.
| S-EPMC4754943 | biostudies-literature
Project description:Cell-encapsulating devices can play an important role in advancing the types of tissue available for transplantation and further improving transplant success rates. To have an effective device, encapsulated cells must remain viable, respond to external stimulus, and be protected from immune responses, and the device itself must elicit a minimal foreign body response. To address these challenges, we developed a micro- and a nanoporous thin-film cell encapsulation device from polycaprolactone (PCL), a material previously used in FDA-approved biomedical devices. The thin-film device construct allows long-term bioluminescent transfer imaging, which can be used for monitoring cell viability and device tracking. The ability to tune the microporous and nanoporous membrane allows selective protection from immune cell invasion and cytokine-mediated cell death in vitro, all while maintaining typical cell function, as demonstrated by encapsulated cells' insulin production in response to glucose stimulation. To demonstrate the ability to track, visualize, and monitor the viability of cells encapsulated in implanted thin-film devices, we encapsulated and implanted luciferase-positive MIN6 cells in allogeneic mouse models for up to 90 days. Lack of foreign body response in combination with rapid neovascularization around the device shows promise in using this technology for cell encapsulation. These devices can help elucidate the metrics required for cell encapsulation success and direct future immune-isolation therapies.
| S-EPMC4628825 | biostudies-literature
Project description:Herein long-term delivery of proteins from biodegradable thin film devices is demonstrated, where a nanostructured polymer membrane controls release. Protein was sealed between two poly(caprolactone) films, which generated the thin film devices. Protein release for 210 days was shown in vitro, and stable activity was established through 70 days with a model protein. These thin film devices present a promising delivery platform for biologic therapeutics, particularly for application in constrained spaces.
| S-EPMC3480309 | biostudies-literature
Project description:Magnetic field sensors based on organic thin-film materials have attracted considerable interest in recent years as they can be manufactured at very low cost and on flexible substrates. However, the technological relevance of such magnetoresistive sensors is limited owing to their narrow magnetic field ranges (∼30 mT) and the continuous calibration required to compensate temperature fluctuations and material degradation. Conversely, magnetic resonance (MR)-based sensors, which utilize fundamental physical relationships for extremely precise measurements of fields, are usually large and expensive. Here we demonstrate an organic magnetic resonance-based magnetometer, employing spin-dependent electronic transitions in an organic diode, which combines the low-cost thin-film fabrication and integration properties of organic electronics with the precision of a MR-based sensor. We show that the device never requires calibration, operates over large temperature and magnetic field ranges, is robust against materials degradation and allows for absolute sensitivities of <50 nT Hz(-1/2).
| S-EPMC3621415 | biostudies-other
Project description:Functional materials with specific surface wettability play an important role in a wide variety of areas. Inspired by nature's Nepenthes pitcher plant, we present a novel slippery film with tunable wettability based on a shape-memory graphene sponge. The porous graphene sponge coated with shape-memory polymer was used to lock in inert lubricants and construct slippery surfaces to repel different liquids. The superelasticity and high strength, together with good electrical conductivity, of the graphene sponge imparted the graphene/polymer hybrid films with fast recoverable shape-memory properties. Various droplets could slip on the compressed film with a lubricant-covered surface, but the droplets would be pinned when the shape-memory graphene film rebounded due to electrical stimulation, which caused the penetration of the infused lubricant into the pores and the exposure of rough topography film surfaces. The electrothermally dynamic tuning approach was stable and reversible; thus, the shape-memory graphene film was imparted with controlled slippery properties and functions that would be amenable to a variety of applications, such as liquid handling for microplates.
| S-EPMC5457146 | biostudies-literature
Project description:Shape Memory Alloy (SMA) materials are widely used as an actuating source for bending actuators due to their high power density. However, due to the slow actuation speed of SMAs, there are limitations in their range of possible applications. This paper proposes a smart soft composite (SSC) actuator capable of fast bending actuation with large deformations. To increase the actuation speed of SMA actuator, multiple thin SMA wires are used to increase the heat dissipation for faster cooling. The actuation characteristics of the actuator at different frequencies are measured with different actuator lengths and results show that resonance can be used to realize large deformations up to 35?Hz. The actuation characteristics of the actuator can be modified by changing the design of the layered reinforcement structure embedded in the actuator, thus the natural frequency and length of an actuator can be optimized for a specific actuation speed. A model is used to compare with the experimental results of actuators with different layered reinforcement structure designs. Also, a bend-twist coupled motion using an anisotropic layered reinforcement structure at a speed of 10?Hz is also realized. By increasing their range of actuation characteristics, the proposed actuator extends the range of application of SMA bending actuators.
| S-EPMC4759690 | biostudies-literature
Project description:We combine numerical simulations and experiments to design a new class of reconfigurable waveguides based on three-dimensional origami-inspired metamaterials. Our strategy builds on the fact that the rigid plates and hinges forming these structures define networks of tubes that can be easily reconfigured. As such, they provide an ideal platform to actively control and redirect the propagation of sound. We design reconfigurable systems that, depending on the externally applied deformation, can act as networks of waveguides oriented along one, two, or three preferential directions. Moreover, we demonstrate that the capability of the structure to guide and radiate acoustic energy along predefined directions can be easily switched on and off, as the networks of tubes are reversibly formed and disrupted. The proposed designs expand the ability of existing acoustic metamaterials and exploit complex waveguiding to enhance control over propagation and radiation of acoustic energy, opening avenues for the design of a new class of tunable acoustic functional systems.
| S-EPMC5262461 | biostudies-literature