Advances in additive manufacturing in composites have transformed aerospace, medical devices, tissue engineering, and electronics. A key aspect of enhancing properties of 3D-printed objects involves fine-tuning the material by embedding and orienting reinforcement within the structure. Existing methods for orienting these reinforcements are limited by pattern types, alignment, and particle characteristics.
View Article and Find Full Text PDFScientists around the world have long aimed to produce miniature robots that can be controlled inside the human body to aid doctors in identifying and treating diseases. Such microrobots hold the potential to access hard-to-reach areas of the body through the natural lumina. Wireless access has the potential to overcome drawbacks of systemic therapy, as well as to enable completely new minimally invasive procedures.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2024
Shape transformation, a key mechanism for organismal survival and adaptation, has gained importance in developing synthetic shape-shifting systems with diverse applications ranging from robotics to bioengineering. However, designing and controlling microscale shape-shifting materials remains a fundamental challenge in various actuation modalities. As materials and structures are scaled down to the microscale, they often exhibit size-dependent characteristics, and the underlying physical mechanisms can be significantly affected or rendered ineffective.
View Article and Find Full Text PDFMultifunctional micromanipulation systems have garnered significant attention due to the growing interest in biological and medical research involving model organisms like zebrafish (). Here, we report a novel acoustofluidic rotational micromanipulation system that offers rapid trapping, high-speed rotation, multi-angle imaging, and 3D model reconstruction of zebrafish larvae. An ultrasound-activated oscillatory glass capillary is used to trap and rotate a zebrafish larva.
View Article and Find Full Text PDFIn recent years, the application of microrobots in precision therapy has gained significant attention. The small size and maneuverability of these micromachines enable them to potentially access regions that are difficult to reach using traditional methods; thus, reducing off-target toxicities and maximizing treatment effectiveness. Specifically, acoustic actuation has emerged as a promising method to exert control.
View Article and Find Full Text PDFSoft polymeric microrobots that can be loaded with nanocargoes and driven external field stimuli can provide innovative solutions in various fields, including precise microscale assembly, targeted therapeutics, microsurgery, and the capture and degradation of unwanted wastewater fragments. However, in aquatic environments, it remains challenging to operate with microrobotic devices due to the predominant viscous resistances and the robots' limited actuation and sensing capabilities attributed to their miniaturization. The miniature size prevents the incorporation of onboard batteries that can provide sufficient power for propulsion and navigation, necessitating a wireless power supply.
View Article and Find Full Text PDFThe intricate and delicate anatomy of the brain poses significant challenges for the treatment of cerebrovascular and neurodegenerative diseases. Thus, precise local drug delivery in hard-to-reach brain regions remains an urgent medical need. Microrobots offer potential solutions; however, their functionality in the brain remains restricted by limited imaging capabilities and complications within blood vessels, such as high blood flows, osmotic pressures, and cellular responses.
View Article and Find Full Text PDFAs a next-generation toolkit, microrobots can transform a wide range of fields, including micromanufacturing, electronics, microfluidics, tissue engineering, and medicine. While still in their infancy, acoustically actuated microrobots are becoming increasingly attractive. However, the interaction of acoustics with microstructure geometry is poorly understood, and its study is necessary for developing next-generation acoustically powered microrobots.
View Article and Find Full Text PDFAchieving controlled mobility of microparticles in viscous fluids can become pivotal in biologics, biotechniques, and biomedical applications. The self-assembly, trapping, and transport of microparticles are being explored in active matter, micro and nanorobotics, and microfluidics; however, little work has been done in acoustics, particularly in active matter and robotics. This study reports the discovery and characterization of microbubble behaviors in a viscous gel that is confined to a slight opening between glass boundaries in an acoustic field.
View Article and Find Full Text PDFBackground: Heroin-Assisted Treatment (HAT) is well evidenced internationally to improve health and social outcomes for people dependent on opioids who have not been helped by traditional treatment options. Despite this evidence base, England has been slow to implement HAT. The first service outside of a trial setting opened in 2019, providing twice-daily supervised injections of medical-grade heroin (diamorphine) to a select sample of high-risk heroin users in Middlesbrough.
View Article and Find Full Text PDFRolling is a ubiquitous transport mode utilized by living organisms and engineered systems. However, rolling at the microscale has been constrained by the requirement of a physical boundary to break the spatial homogeneity of surrounding mediums, which limits its prospects for navigation to locations with no boundaries. Here, in the absence of real boundaries, we show that microswarms can execute rolling along virtual walls in liquids, impelled by a combination of magnetic and acoustic fields.
View Article and Find Full Text PDFLiquid manipulation is the foundation of most laboratory processes. For macroscale liquid handling, both do-it-yourself and commercial robotic systems are available; however, for microscale, reagents are expensive and sample preparation is difficult. Over the last decade, lab-on-a-chip (LOC) systems have come to serve for microscale liquid manipulation; however, lacking automation and multi-functionality.
View Article and Find Full Text PDFPurpose: To describe characteristics of indocyanine green (ICG) angiographic plaques in the nonexudative fellow eye of White patients with unilateral treatment-naïve exudative neovascular age-related macular degeneration through optical coherence tomography (OCT) and OCT angiography (OCTA).
Methods: In this retrospective cross-sectional study, nonexudative eyes with ICG angiographic plaques were analyzed by OCT B-scans for the sensitivity of a double-layer sign, a pigment epithelium detachment, outer retinal atrophy, hyperreflective dots, and subretinal hyperreflective material (SRHM). The ICG angiographic plaque was matched with a macular neovascularization in OCTA en face scans and color-coded B scans.
Existing single-cell adhesion kinetics methods are performed under conditions highly unlike the physiological cell adhesion conditions. Now, researchers have developed a new optical technique for high-precision measurement of cell lateral adhesion kinetics in complex clinical samples.
View Article and Find Full Text PDFIn vivo micromanipulation using ultrasound is an exciting technology with promises for cancer research, brain research, vasculature biology, diseases, and treatment development. In the present work, we demonstrate in vivo manipulation of gas-filled microparticles using zebrafish embryos as a vertebrate model system. Micromanipulation methods often are conducted in vitro, and they do not fully reflect the complex environment associated in vivo.
View Article and Find Full Text PDFCilia are short, hair-like appendages ubiquitous in various biological systems, which have evolved to manipulate and gather food in liquids at regimes where viscosity dominates inertia. Inspired by these natural systems, synthetic cilia have been developed and utilized in microfluidics and microrobotics to achieve functionalities such as propulsion, liquid pumping and mixing, and particle manipulation. Here, we demonstrate ultrasound-activated synthetic ciliary bands that mimic the natural arrangements of ciliary bands on the surface of starfish larva.
View Article and Find Full Text PDFPurpose: A model was calculated during the first Austrian coronavirus disease-2019 (COVID-19) pandemic lockdown to estimate the effect of a short-term treatment interruption due to healthcare restrictions on visual acuity (VA) in neovascular age-related macular degeneration (nAMD). The model was compared to the real-life outcomes before treatment re-started.
Methods: Retrospective data-collection of 142 eyes in 142 patients receiving repeated intravitreal injections with anti-VEGF at a retina unit in Vienna in a personalized pro-re-nata regimen prior to the COVID-19 associated lockdown, when treatment was deferred between March 16 and May 4, 2020.
Purpose: To evaluate the capability of swept source-optical coherence tomography angiography (SS-OCTA) in the detection and localization of treatment-naive macular neovascularization (MNV) secondary to exudative neovascular age-related macular degeneration (nAMD).
Methods: In this prospective, observational case series, 158 eyes of 142 patients were diagnosed with exudative nAMD using fluorescein (FA) and indocyanine green angiography (ICGA) and evaluated by SS-OCTA in a tertiary retina center (Rudolf Foundation Hospital Vienna, Austria). The main outcome measure was the sensitivity of SS-OCTA compared to the standard multimodal imaging approach.
Introduction: To evaluate the effect of a 9-week treatment deferral due to healthcare restrictions caused by Austria's first governmental lockdown associated with the coronavirus disease 2019 (COVID-19) pandemic on visual acuity (VA) in eyes compromised by exudative neovascular age-related macular degeneration (nAMD) after 1 year.
Methods: Retrospective data collection of 98 eyes (98 patients) with a treatment discontinuation at a tertiary eye care center (Clinic Landstraße, Vienna Healthcare Group, Austria) between March 16 and May 4, 2020. Prior to the lockdown, patients received multiple intravitreal injections (IVI) of anti-vascular endothelial growth factor with a personalized treatment interval for 3 years on average and at least three IVI after the lockdown.
Nat Mach Intell
February 2021
The ability to propel against flows, i.e., to perform positive rheotaxis, can provide exciting opportunities for applications in targeted therapeutics and non-invasive surgery.
View Article and Find Full Text PDFAcoustically excited microstructures have demonstrated significant potential for small-scale biomedical applications by overcoming major microfluidic limitations. Recently, the application of oscillating microbubbles has demonstrated their superiority over acoustically excited solid structures due to their enhanced acoustic streaming at low input power. However, their limited temporal stability hinders their direct applicability for industrial or clinical purposes.
View Article and Find Full Text PDFThe purpose was to demonstrate the diagnostic and therapeutic feasibility of swept source-optical coherence tomography angiography (SS-OCTA) by picturing neovascular changes secondary to a rare white dot syndrome following long-term intravitreal ranibizumab (IVR). A 28-year-old Caucasian myopic female presented with visual loss in her right eye only. The clinical examination and multimodal imaging including spectral domain (SD)-OCT, blue-peak autofluorescence, fluorescein, and indocyanine green angiography (HRA Spectralis, Heidelberg Engineering; Heidelberg, Germany) as well as SS-OCTA (DRI Triton, Topcon; Tokyo, Japan) led to the diagnosis of idiopathic punctate inner choroidopathy with secondary subfoveal choroidal neovascularization (CNV).
View Article and Find Full Text PDFQuantitative micromechanical characterization of single cells and multicellular tissues or organisms is of fundamental importance to the study of cellular growth, morphogenesis, and cell-cell interactions. However, due to limited manipulation capabilities at the microscale, systems used for mechanical characterizations struggle to provide complete three-dimensional coverage of individual specimens. Here, we combine an acoustically driven manipulation device with a micro-force sensor to freely rotate biological samples and quantify mechanical properties at multiple regions of interest within a specimen.
View Article and Find Full Text PDFMagnetic dipole-dipole interactions govern the behavior of magnetic matter across scales from micrometer colloidal particles to centimeter magnetic soft robots. This pairwise long-range interaction creates rich emergent phenomena under both static and dynamic magnetic fields. However, magnetic dipole particles, from either ferromagnetic or paramagnetic materials, tend to form chain-like structures as low-energy configurations due to dipole symmetry.
View Article and Find Full Text PDFAn amendment to this paper has been published and can be accessed via the original article.
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