Printed-Sensor-on-Chip devices – Aerosol jet deposition of thin film relative humidity sensors onto packaged integrated circuits

In this paper we report on the development of an aerosol jet printed sensing platform integrating elements of silicon and printed electronics. To demonstrate the technology, thin film humidity sensors have been fabricated over the top surface and sides of pre-packaged integrated circuits using a combination of direct-write aerosol jet deposition and drop-casting. The resistive based sensor consists of an aerosol jet deposited interdigitated nano-particle silver electrode structure overlaid with a thin film of Nafion® acting as a humidity sensitive layer. The fabricated sensor displayed a strong response to changes in relative humidity over the tested range (40% RH to 80% RH) and showed a low level of hysteresis whilst undergoing cyclic testing. The successful fabrication of relative humidity sensors over the surface and pins of a packaged integrated circuit demonstrates a new level of integration between printed and silicon based electronics − leading to Printed-Sensor-on-Chip devices. Whilst demonstrated for humidity, the proposed concept is envisaged to work as a platform for a wide range of applications, from bio-sensing to temperature or gas monitoring

Creating Customized Hip-Spacers Using PMMA-Based Green Composites to Fulfill Specific Needs of Individuals with Disabilities

In the context of replacing damaged artificial hip joints, a common practice involves using antibiotic-infused bone cement as a spacer. However, the mechanical properties of polymethyl methacrylate (PMMA), which is commonly used for spacers, have certain limitations. To address this issue, the present study suggests incorporating a natural filler, specifically coffee husk, as a reinforcement for PMMA. Different composite samples were prepared by varying the weight fractions of coffee husk, and their mechanical properties were assessed. The results indicated that the inclusion of coffee husk particles in PMMA led to improvements in compressive strength, hardness, and stiffness. Furthermore, a finite element model was constructed and analyzed to evaluate the stress experienced on the spacer’s surface (load-carrying capacity), yielding findings consistent with the experimental results

Utilizing photothermally induced oscillation damping parameters for the determination of bacterial load suspended in microfluidic resonators

Microchannel resonators containing a miniaturized volume of a solution can have various applications in different fields. In this study, a microchannel cantilever was loaded with a solution containing a very small number of Pseudomonas fluorescens bacteria suspended in M9 growth medium. The liquid-filled microchannel cantilever was irradiated with a 532-nm laser. The shift in the frequency of the cantilever due to varying bacterial loads is less reliable; therefore, it could not be used for monitoring the bacterial concentration. The energy loss of the cantilever extracted from the quality factor exhibited reliable results and a very strong correlation with the bacterial concentration. The results showed a linear relation between the damping factor of the cantilever and the bacterial concentration. Accordingly, these findings were expected because the bacteria inside the solution can be considered as particles acting against the cantilever motion due to the solution’s viscosity. Thus, more bacteria caused more damping, in agreement with the experimental observations. A semiquantitative experiment was conducted with a heat source (i.e., laser beam) that focused at the cantilever tip to demonstrate the redistribution of the bacterial load within the solution due to the thermal gradient

Nanotechnology and Prosthetic Devices: Integrating Biomedicine and Materials Science for Enhanced Performance and Adaptability

Nanomaterials are revolutionizing prosthetic device development. Nanotechnology has made prosthetic devices that replicate natural limb behavior and respond to users’ intentions possible. Nanomaterials improve prosthetic functionality, comfort, and lifespan. Nanocomposites, smart sensors, and medication delivery systems have addressed mechanical strength, control, and biocompatibility, resulting in enhanced prosthetic devices that improve user freedom, mobility, and quality of life. Biomedicine and materials science have helped nanomaterials reach their full potential, enabling their seamless integration into prosthetic devices and fostering interdisciplinary collaborations that advance prosthetics. The literature study shows substantial advances in nanomaterials for prosthetic devices; however, various gaps in present research and possible future research areas are indicated. First, long-term biocompatibility studies are needed to understand nanomaterials’ long-term effects on humans. Nanomaterial-based prosthetic devices must be tested and researched to assure safety and efficacy in real-world situations. Second, nanocomposites and nanoscale components must be standardized and quality-controlled to enable consistency and scalability in prosthetic devices. Third, nanoscale sensor and neural interface ethics must address privacy, security, and user consent issues. The nanomaterial-based prosthetic devices must be made more inexpensive and accessible to more disabled people. The study design was carried out to incorporate significant literature on the application of nanotechnology related to prosthetic devices. The literature was filtered from the Scopus database. The selected literature belongs to the original articles in which experimental work was carried out. Future research could combine nanotechnology with other developing technologies like artificial intelligence and robotics to produce more advanced and adaptable prosthetic devices

Ruthenium nanoparticles doped on electrochemical activated screen-printed electrode for simultaneous determination of dopamine and paracetamol in pharmaceutical and human serum samples

A simple and highly selective electrochemical method using the commercially available screen-printed electrode electrochemically activated (ASPE) by cyclic voltammetry in 1.0 M H2SO4 and modified with ruthenium nanoparticles (RuNPs) was developed for the simultaneous determination of dopamine (DA) and paracetamol (PA). Changes in electrochemical behavior before and after the electrochemical activation of ASPE were studied by CV and EIS. The results have shown that the electrochemical activation of ASPE can improves the electrical conductivity, large surface area, and thus resulting in the formation of conducting RuNPs/ASPE nanocomposite. The morphologies and interface properties of the obtained RuNPs/ASPE nanocomposite were examined by FE–SEM, TEM, EDX, XRD, and AFM. Moreover, the electrochemical performances of the nanocomposite were investigated by CV, EIS and SWV methods. After optimization, the results show that CV, SWV, and EIS can effectively detect DA and PA using the fabricated sensor. For individual detection, SWV and EIS proved to be better techniques, particularly SWV, which exhibited the highest sensitivity (1.93 and 1.06 μA mM−1 cm−2) and the lowest detection limits (0.11 μM for DA and 0.17 μM for PA). However, for simultaneous detection, CV is more advantageous, providing the widest linear ranges (1.0–300 μM for DA and 1.0–400 μM for PA). Furthermore, the newly RuNPs/ASPE sensor showed excellent repeatability, reproducibility, stability, and selectivity. This sensor was successfully applied to measure PA and DA in both human blood and pharmaceutical formulations with satisfactory recovery

Thiol-SAM Concentration Effect on the Performance of Interdigitated Electrode-Based Redox-Free Biosensors

Despite the direct, redox-free and simple detection non-faradaic impedimetric biosensors offer, considerable optimizations are required to enhance their performance for the detection of various biomarkers. Non-faradaic EIS sensors’ performance depends on the interfacial capacitance between a polarized biosensor surface and the tested sample solution. Careful engineering and design of the interfacial capacitance is encouraged to magnify the redout signal upon bioreceptor–antigen interactions. One of the methods to achieve this goal is by optimizing the self-assembled monolayer concentration, which has not been reported for non-faradaic impedimetric sensors. Here, the impact of alkanethiolate (cysteamine) concentration on the performance of gold (Au) interdigitated electrode (Au-IDE) biosensors is reported. Six sets of biosensors were prepared, each with a different cysteamine concentration: 100 nM, 1 μM, 10 μM, 100 μM, 1 mM, and 10 mM. The biosensors were prepared for the direct detection of LDL cholesterol by attaching LDL antibodies on top of the cysteamine via a glutaraldehyde cross-linker. As the concentration of cysteamine increased from 100 nM to 100 μM, the sensitivity of the biosensor increased from 6.7 to 16.2 nF/ln (ng/mL). As the cysteamine concentration increased from 100 μM to 10 mM, the sensitivity deteriorated. The limit of detection (LoD) of the biosensor improved as the cysteamine increased from 100 nM to 100 μM (i.e., 400 ng/mL to 59 pg/mL). However, the LoD started to increase to 67 pg/mL and 16 ng/mL for 1 mM and 10 mM cysteamine concentrations, respectively. This shows that the cysteamine concentration has a detrimental effect on redox-free biosensors. The cysteamine layer has to be as thin as possible and uniformly cover the electrode surfaces to maximize positive readout signals and reduce negative signals, significantly improving both sensitivity and LoD

Evaluating the Performance of 3D-Printed PLA Reinforced with Date Pit Particles for Its Suitability as an Acetabular Liner in Artificial Hip Joints

Off-the-shelf hip joints are considered essential parts in rehabilitation medicine that can help the disabled. However, the failure of the materials used in such joints can cause individual discomfort. In support of the various motor conditions of the influenced individuals, the aim of the current research is to develop a new composite that can be used as an acetabular liner inside the hip joint. Polylactic acid (PLA) can provide the advantage of design flexibility owing to its well-known applicability as a 3D printed material. However, using PLA as an acetabular liner is subject to limitations concerning mechanical properties. We developed a complete production process of a natural filler, i.e., date pits. Then, the PLA and date pit particles were extruded for homogenous mixing, producing a composite filament that can be used in 3D printing. Date pit particles with loading fractions of 0, 2, 4, 6, 8, and 10 wt.% are dispersed in the PLA. The thermal, physical, and mechanical properties of the PLA–date pit composites were estimated experimentally. The incorporation of date pit particles into PLA enhanced the compressive strength and stiffness but resulted in a reduction in the elongation and toughness. A finite element model (FEM) for hip joints was constructed, and the contact stresses on the surface of the acetabular liner were evaluated. The FEM results showed an enhancement in the composite load carrying capacity, in agreement with the experimental results

Developing PMMA/Coffee Husk Green Composites to Meet the Individual Requirements of People with Disabilities: Hip Spacer Case Study

When replacing a damaged artificial hip joint, treatment involves using antibiotic-laced bone cement as a spacer. One of the most popular materials used for spacers is PMMA; however, it has limitations in terms of mechanical and tribological properties. To overcome such limitations, the current paper proposes utilizing a natural filler, coffee husk, as a reinforcement for PMMA. The coffee husk filler was first prepared using the ball-milling technique. PMMA composites with varying weight fractions of coffee husk (0, 2, 4, 6, and 8 wt.%) were prepared. The hardness was measured to estimate the mechanical properties of the produced composites, and the compression test was utilized to estimate the Young modulus and compressive yield strength. Furthermore, the tribological properties of the composites were evaluated by measuring the friction coefficient and wear by rubbing the composite samples against stainless steel and cow bone counterparts under different normal loads. The wear mechanisms were identified via scanning electron microscopy. Finally, a finite element model for the hip joint was built to investigate the load-carrying capacity of the composites under human loading conditions. The results show that incorporating coffee husk particles can enhance both the mechanical and tribological properties of the PMMA composites. The finite element results are consistent with the experimental findings, indicating the potential of the coffee husk as a promising filler material for enhancing the performance of PMMA-based biomaterials