Micro and Nanosystems - Volume 15, Issue 2, 2023

Smart healthcare is a healthcare delivery method that utilizes wearable devices, the internet of things, and the mobile internet to dynamically access information, connect people, materials, and institutions in the healthcare industry, and then intelligently monitor and respond to the medical ecosystem requirements. The concept of smart healthcare has progressively gained traction as information technology advances like Telemedicine and Robotics. The purpose of the internet of things (IoT) is to connect many effects and items present in the surroundings so they may communicate and work together "anytime, anywhere, with anything and anyone, flawlessly using any path or network and any service."Smart healthcare employs a new generation of information technologies, such as the IoT, big data, cloud computing, and artificial intelligence, to completely revolutionize the existing medical system, making it more efficient, easy, and personalized. Thereby, to introduce the concept of “smart healthcare”, foremost, we identify the essential technologies that support it and discuss the current state of smart healthcare in a few key areas.

Background: Lipid nanocarriers (NLCs) have undergone significant research over the past two decades to determine how well they target drugs to important parts of the human body, such as the central nervous system (CNS), the heart region, tumor cells, etc. Objective: The objective of this review paper was to review and critically summarize recent progress in NLC for targeting CNS. Methods: The structure, classification, elements, and numerous preparation techniques have been carefully outlined in this paper, along with their benefits and drawbacks, as demonstrated by several research investigations. Results: This review focuses on recent developments in NLCs for brain targeting of bioactives with special attention to their surface modifications, formulation aspects, pharmacokinetic behavior, and effectiveness for treating a variety of brain disorders. Conclusion: Poorly water-soluble bioactive substances’ physicochemical properties and behavior, such as aqueous dispersibility and oral bioavailability, can be greatly improved using lipid nanocarriers. Due to the brain's complicated structure and numerous protective systems, drug distribution to the brain has remained a difficult problem for scientists. The employment of an appropriate nanocarrier technology and an alternate drug delivery method, such as nose-to-brain drug delivery, could overcome the problem of brain targeting and increase the therapeutic effectiveness of CNS-acting medications. The pharmaceutical business has recently transformed various innovative drug delivery methods that address the drawbacks of conventional drug delivery systems and offer a good benefit-to-risk ratio.

Additive Manufacturing (AM) is considered one of the key technologies for realizing Industry 4.0. There are numerous stages in the end-to-end AM process, including component design, material design, build, and so on. An enormous amount of data is generated along the end-to-end AM process that can be acquired from the 3D printer in real-time, micro-characterization studies, and process plan details, among others. For instance, these data can be employed to predict the printed components’ quality and, at the same time, proactively adapt the 3D printer parameters to achieve better quality. This end-to-end AM process can be mapped onto the digital thread. The current article elaborates on a conceptual framework to acquire the data from various sources associated with the end-to-end AM process and realize monitoring and control of the end-to-end AM process, leading to an intelligent AM process.

Background: The thermal time constant is the core parameter for determining the dynamic response of the electrothermal actuators and the corresponding maximum operational frequency. Aim: Since it is necessary to determine how the thermal actuation occurs within the cantilever, this paper presents two models for the thermal time constant of bimetal microcantilevers. One model is based on the bimetallic effect, and the second is based on temperature gradients in layers. Methods: In order to investigate and check the validity of the two proposed models, the device was actuated electrothermally, and the thermal time response was estimated. A driving voltage was applied to the platinum electrode. The first model is based on the interface thermal resistance between the base and the top electrode layer. The second model assumes that the temperature gradients within the base layer are responsible for thermal actuation. Results: The microcantilever was excited electrothermally with a resonance frequency of 1.89 MHz. The bimetallic effect was found to be less able to stimulate the microcantilever at this resonance frequency. Therefore, it was concluded that thermal actuation occurred as a result of temperature variation within the SiC base layer. Conclusion: The results also indicated that temperature variations within one of the two materials in contact might be responsible for thermal actuation, especially if the material has high thermal conductivity.

Background: Heterostructures with nanoscale sizes have great superiorities in photocatalytic environment decontaminant because of their efficient interface charge transfer and great surface area. Objective: This work reports the facile fabrication of nano-tubular TiO2 and Si-doped TiO2 (NTs) hybridizing SnS nanocrystallites and their high-efficient photocatalytic activity. Methods: The modified hydrothermal processes were used to synthesize the nanotubes. A chemical bath deposition process was used to hybridize SnS nanocrystalline with the nanotubes. Results: The fabricated nanostructures show wide light absorption in the UV-visible region. The SBET, light absorption, hydrophilicity, and photo-induced super hydrophilicity were enhanced by Si-doping and SnS modification. Moreover, high-efficient interface charge transfer was produced after the SnS modification and further enhanced by the Si doping because of band structure modulation. Conclusion: Thus, the Si-doped TiO2 nanotubes/SnS heterostructures showed remarkably enhanced photocatalytic and Fenton-like photocatalytic activity in dye wastewater treatment than the TiO2 NTs. This work suggests potential materials and their facile fabrication process for the photocatalytic application of environmental decontamination.

Aim: Construction of electrochromic device via Prussian yellow nanofilm on glass electrode. Background: Energy conservation is one of the primary research topics nowadays. Electrochromic devices with low power consumption and short stable switching periods are well suited to energyefficient applications, e.g., smart windows, car mirrors, displays, and electronic papers. Objective: Preparation of electrochromic Prussian yellow nanofilm on ITO glass by a simple chemical facile method and study of its electrochromic features. Methods: Prussian yellow nanofilm (iron (III) hexacyanoferrate (III)), was prepared by immersing the substrate in a solution of ferric nitrate and Potassium hexacyanoferrate. Prussian yellow nanofilm is characterized by ultraviolet-visible (Uv-Vis) spectroscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Prussian yellow nanofilm shows an intense yellow color when it is in a pristine state. Results: Resultant Prussian yellow nanofilm underwent reversible redox reactions accompanied by color changes from Prussian yellow to Prussian green to further Prussian blue, then to Prussian white. The transmittance of Prussian yellow nanofilm varies from 21% for colored state at 450nm to 81 % (for fully bleached) at 0.9V. The contrast ratio and ratio of optical density to charge density were examined and the coloration efficiency was calculated to be 299.6 cm²C^-1. Conclusion: Prussian yellow can be very simply prepared and used as an efficient, fast switching electrochromic device with high color contrast.

Background: Atleast once in life everyone experience different kinds of dermal diseases and the conventional dosage forms having a high rate of side effects. The discussed method is a better and alternative approach in case of patients’ compliance and sustained drug release. Objective: The objectives of this study are to prepare solid dispersion for enhancement of solubility of roxithromycin, encapsulation of solid dispersion into microspheres, decreased dose frequency, sustained release and incorporation of microspheres in in situ gel for easy utilization and adherence over the skin in microbial infection. Methods: Solid dispersion of roxithromycin and HPMC at a ratio of 1:1 was prepared by the melting method, and solubility was measured by in vitro dissolution rate. On the basis of 3² factorial design, 9 different formulations were evaluated by % drug release, particle size, and % entrapment efficiency. Lastly, in situ gel was prepared by a cold method, which was evaluated through gelling time and temperature; in vitro gelation method. Results: The solid dispersion was found to have a 1.3 times higher solubility than pure roxithromycin as proven by in vitro drug release. Whereas, microsphere MF-9 was selected as the best formulation via drug release (87.81%), entrapment efficiency (91.223%), % yield (86.681), and particle size (110μm). In-situ gel MIG-5 was selected as the best formulation on the basis of drug content (89.326±0.564), viscosity (9551.666 ± 6.233), and gelling time (25.333±2.054). Conclusion: Solid dispersion was prepared successfully with higher solubility than the pure drug. Microspheres have shown sustained drug release and in situ gels have a good adhesive property and MIG-5 further enhances the sustained drug release behaviour.

Background: Metal surface modification of the photocatalysts is effective for enhancing the photocatalytic properties of the semiconductor photocatalysts. Nd can be used as the modified metal for the enhancement of catalytic performance of the strontium tin hydroxide (SrSn(OH)6) nanorods due to expanding the light absorption range and reducing the recombination of the photo-generated electrons and holes. Objective: The aim of the research is to synthesize Nd-modified SrSn(OH)6 nanorods and investigate the enhanced photocatalytic performance for crystal violet degradation. Methods: Nd modified SrSn(OH)6 nanorods were prepared via a facile one-step in-situ photodeposition route. The obtained nanorods were analyzed by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, solid diffuse reflectance spectra, photoluminescence spectroscopy, and electrochemical impedance spectroscopy. Results: Nd attached to the surface of nanorods. The band gap of the Nd-modified SrSn(OH)6 nanorods was reduced due to Nd modification at the surface of nanorods. The Nd-modified SrSn(OH)6 nanorods showed enhanced photocatalytic properties for crystal violet (CV) degradation under ultraviolet (UV) light irradiation than the SrSn(OH)6 nanorods. Nd modified SrSn(OH)6 nanorods have lower charge transfer resistance and more efficient charge separation ability, thus hindering the recombination of the electrons and holes (e⁻/h⁺) pairs. Scavenger experiments reported that the holes, superoxide, and hydroxyl radicals are the main reactive species during the photocatalytic reaction. The Ndmodified SrSn(OH)6 nanorods were found to be recoverable and reusable for CV degradation. Conclusion: The Nd modified SrSn(OH)6 nanorods showed enhanced photocatalytic performance towards crystal violet than un-modified nanorods.

Background: Atomic Force Microscopy (AFM) nanoindentation is the principal method for the characterization of soft materials at the nanoscale. In most cases, pyramidal tips are used and approximated to perfect cones. However, the extended use of the AFM tip may alter its sharpness. Objective: In many cases, a truncated cone shape is appropriate for tip modeling. In this technical note, the equation that relates the force with the indentation depth when indenting an elastic halfspace using a truncated cone is derived. Methods: The nanoindentation equation for a truncated cone tip is derived using the fundamental differential equation that relates the sample’s contact stiffness with Young’s modulus. Results: When fitting Sneddon’s equation (which is valid for a perfect cone) on data obtained using a truncated cone-shaped AFM tip, the results show a ‘pseudo-softening’ behavior. Conclusion: The AFM tip's sharpness in nanoindentation experiments is a crucial parameter for obtaining the correct mechanical patterns of unknown samples.