Cellulosic fibers from kenaf bast were isolated in three distinct stages. Initially raw kenaf bast fibers were subjected to an alkali pulping process. Then pulped fibers undergone a bleaching process and finally both pulped and bleached fibers were separated into their constituent nanoscale cellulosic fibers by mechanical shearing. The influence of each treatment on the chemical composition of fibers was investigated. Moreover morphology, functional groups, crystallinity, and thermal behavior of fiber hierarchy at different stages of purification were studied using scanning and transmission electron microscopies, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. Microscopy studies revealed that applied procedures successfully isolated nanoscale cellulosic fibers from both unbleached and bleached pulps. Chemical composition analysis and FTIR spectroscopy showed that lignin and hemicellulose were almost entirely removed by the applied treatments. XRD and TGA analyses demonstrated progressive enhancement of properties in fibers, hierarchically, in going from micro to nano scale. Interestingly no significant evolution was observed between obtained data of characterized ubnleached and bleached nanofibers.
This paper reports a method that enables real-time displacement monitoring and control of micromachined resonant-type actuators using wireless radiofrequency (RF). The method is applied to an out-of-plane, spiral-coil microactuator based on shape-memory-alloy (SMA). The SMA spiral coil forms an inductor-capacitor resonant circuit that is excited using external RF magnetic fields to thermally actuate the coil. The actuation causes a shift in the circuit's resonance as the coil is displaced vertically, which is wirelessly monitored through an external antenna to track the displacements. Controlled actuation and displacement monitoring using the developed method is demonstrated with the microfabricated device. The device exhibits a frequency sensitivity to displacement of 10 kHz/µm or more for a full out-of-plane travel range of 466 µm and an average actuation velocity of up to 155 µm/s. The method described permits the actuator to have a self-sensing function that is passively operated, thereby eliminating the need for separate sensors and batteries on the device, thus realizing precise control while attaining a high level of miniaturization in the device.
Optical vorticesare generated and controlled to form trapping tools in the same way as optical tweezers. By using the intense optical vortices generated within the PANDA ring resonator, the required atoms/molecules can be trapped and moved (transported) dynamically within the wavelength router or network. The advantage of the proposed system is that a transmitter and receiver can be formed within the same system, which is available for atoms/molecules storage and transportation based on methods that have been proposed to deliver drugs into cells for specific diagnosis.
This paper reports the wireless Shape-Memory-Polymer actuator operated by external radio frequency magnetic fields and its application in a drug delivery device. The actuator is driven by a frequency-sensitive wireless resonant heater which is bonded directly to the Shape-Memory-Polymer and is activated only when the field frequency is tuned to the resonant frequency of heater. The heater is fabricated using a double-sided Cu-clad Polyimide with much simpler fabrication steps compared to previously reported methods. The actuation range of 140 μm as the tip opening distance is achieved at device temperature 44 °C in 30 s using 0.05 W RF power. A repeatability test shows that the actuator's average maximum displacement is 110 μm and standard deviation of 12 μm. An experiment is conducted to demonstrate drug release with 5 μL of an acidic solution loaded in the reservoir and the device is immersed in DI water. The actuator is successfully operated in water through wireless activation. The acidic solution is released and diffused in water with an average release rate of 0.172 μL/min.
This paper reports on the fabrication and characterization of a Complementary Metal Oxide Semiconductor-Microelectromechanical System (CMOS-MEMS) device with embedded microheater operated at relatively elevated temperatures (40 °C to 80 °C) for the purpose of relative humidity measurement. The sensing principle is based on the change in amplitude of the device due to adsorption or desorption of humidity on the active material layer of titanium dioxide (TiO2) nanoparticles deposited on the moving plate, which results in changes in the mass of the device. The sensor has been designed and fabricated through a standard 0.35 µm CMOS process technology and post-CMOS micromachining technique has been successfully implemented to release the MEMS structures. The sensor is operated in the dynamic mode using electrothermal actuation and the output signal measured using a piezoresistive (PZR) sensor connected in a Wheatstone bridge circuit. The output voltage of the humidity sensor increases from 0.585 mV to 30.580 mV as the humidity increases from 35% RH to 95% RH. The output voltage is found to be linear from 0.585 mV to 3.250 mV as the humidity increased from 35% RH to 60% RH, with sensitivity of 0.107 mV/% RH; and again linear from 3.250 mV to 30.580 mV as the humidity level increases from 60% RH to 95% RH, with higher sensitivity of 0.781 mV/% RH. On the other hand, the sensitivity of the humidity sensor increases linearly from 0.102 mV/% RH to 0.501 mV/% RH with increase in the temperature from 40 °C to 80 °C and a maximum hysteresis of 0.87% RH is found at a relative humidity of 80%. The sensitivity is also frequency dependent, increasing from 0.500 mV/% RH at 2 Hz to reach a maximum value of 1.634 mV/% RH at a frequency of 12 Hz, then decreasing to 1.110 mV/% RH at a frequency of 20 Hz. Finally, the CMOS-MEMS humidity sensor showed comparable response, recovery, and repeatability of measurements in three cycles as compared to a standard sensor that directly measures humidity in % RH.
A suitable and cost-effective microfabrication technique for processing aluminum micropart is required, as the choice
of aluminum microparts for aerospace, electronics and automobile components is preferred over other metals due to its
excellent properties. Meanwhile, powder injection molding (PIM) is identified as an economical manufacturing technique
for processing ceramic and micro-metal powders into microparts and or components. Therefore, this study investigates
formulation and processing of aluminum PIM feedstock using a custom-made machine. The investigation is focused on
the effect of mixing process parameters (powder loading, rotor speed and mixing temperature) and the suitability of
the backbone polymer. The formulated PIM feedstock constituents are paraffin wax (PW), stearic acid (SA), high-density
polyethylene (HDPE)/ medium-density polyethylene (MDPE) alternatively and aluminum micro-metal powder. Taguchi
method is used for the design of experiments (DOEs) and analysis. In addition, response surface methodology (RSM) is
employed to develop empirical viscosity models. The optimum powder-binder mixing ratio of 58:42 vol. % with rotor
speed of 43 rpm were determined for preparing aluminum PIM feedstock using mini-lab mixer developed. The empirical
model developed for aluminum PIM feedstock viscosity shows a good fit with R2
values of 0.84 using HDPE and 0.96 for
MDPE binder system. This investigation demonstrates preparation and suitability of aluminum PIM feedstock using waxbased
binder system.
A novel microextraction technique termed solid phase membrane tip extraction (SPMTE) was developed. Selected triazine herbicides were employed as model compounds to evaluate the extraction performance and multiwall carbon nanotubes (MWCNTs) were used as the adsorbent enclosed in SPMTE device. The SPMTE procedure was performed in semi-automated dynamic mode and several important extraction parameters were comprehensively optimized. Under the optimum extraction conditions, the method showed good linearity in the range of 1-100 microg/L, acceptable reproducibility (RSD 6-8%, n=5), low limits of detection (0.2-0.5 microg/L), and satisfactory relative recoveries (95-101%). The SPMTE device could be regenerated and reused up to 15 analyses with no analyte carry-over effects observed. Comparison was made with commercially available solid phase extraction-molecular imprinted polymer cartridge (SPE-MIP) for triazine herbicides as the reference method. The new developed method showed comparable or even better results against reference method and is a simple, feasible, and cost effective microextraction technique.
Developing new treatments for emerging infectious diseases in infectious and noninfectious diseases has attracted a particular attention. The emergence of viral diseases is expected to accelerate; these data indicate the need for a proactive approach to develop widely active family specific and cross family therapies for future disease outbreaks. Viral disease such as pneumonia, severe acute respiratory syndrome type 2, HIV infection, and Hepatitis-C virus can cause directly and indirectly cardiovascular disease (CVD). Emphasis should be placed not only on the development of broad-spectrum molecules and antibodies but also on host factor therapy, including the reutilization of previously approved or developing drugs. Another new class of therapeutics with great antiviral therapeutic potential is molecular communication networks using deep learning autoencoder (DL-AEs). The use of DL-AEs for diagnosis and prognosis prediction of infectious and noninfectious diseases has attracted a particular attention. MCN is map to molecular signaling and communication that are found inside and outside the human body where the goal is to develop a new black box mechanism that can serve the future robust healthcare industry (HCI). MCN has the ability to characterize the signaling process between cells and infectious disease locations at various levels of the human body called point-to-point MCN through DL-AE and provide targeted drug delivery (TDD) environment. Through MCN, and DL-AE healthcare provider can remotely measure biological signals and control certain processes in the required organism for the maintenance of the patient's health state. We use biomicrodevices to promote the real-time monitoring of human health and storage of the gathered data in the cloud. In this paper, we use the DL-based AE approach to design and implement a new drug source and target for the MCN under white Gaussian noise. Simulation results show that transceiver executions for a given medium model that reduces the bit error rate which can be learned. Then, next development of molecular diagnosis such as heart sounds is classified. Furthermore, biohealth interface for the inside and outside human body mechanism is presented, comparative perspective with up-to-date current situation about MCN.