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Abstract: Herein, the cost-effective utilization of biosorption for toxic pollutant removal was investigated, with a specific emphasis on enhancing mushroom-based biosorbents for the decontamination of heavy metals-polluted aqueous environments. Firstly, Oyster mushrooms (Pleurotus ostreatus) collected from Bajaur, Khyber Pakhtunkhwa, Pakistan, underwent thorough cleaning, followed by air-drying for 2–3 weeks to produce a fine powder. The obtained powder was subjected to thermal modification through heating at 400°C/1 h, and a portion of it was additionally modified using potassium hydroxide (KOH). This process resulted in three distinct materials: untreated dried mushroom (AM), thermally modified mushroom (TMM), and chemically modified mushroom (CMM), and their chemical compositions were assessed using Fourier Transform Infrared (FTIR) spectroscopy. Subsequently, the resulting materials were employed as bioadsorbents for the elimination of toxic Fe(III) ions from aqueous media. Various experimental variables, including solution pH, temperature, contact time, pollutant concentration, and adsorbent amount were varied to investigate their impact on adsorption. Analysis using an atomic absorption spectrophotometer (AAS) demonstrated exceptional Fe(III) removal capacities of mushrooms, achieving a removal extent of 29.99 mg/g at 303 K, pH 6.0, and an adsorbent dosage of 0.1 g/L, resulting in a remarkable 99.97% removal efficiency. The type of adsorbent significantly affected the extent of adsorption. Furthermore, thermodynamic analysis revealed that adsorption was spontaneous and exothermic. The adsorption data were evaluated using Langmuir, Freundlich, and Temkin isotherms, with the pseudo-second-order reaction kinetics providing the best fit, suggesting that chemisorption predominates the surface adsorption of Fe(III). This study highlights the potential of mushroom-based biosorbents as eco-friendly and effective materials for purifying water contaminated with toxic pollutants.

In this study, we propose a miniaturized triple-band multiple-input-multiple-output (MIMO) implantable antenna having four ports designed for the real-time transmission of high-quality images and videos for wireless capsule endoscopy (WCE) and deep tissue applications. The proposed antenna operates in the industrial, scientific, and medical (ISM) bands of 0.902–0.928 GHz for data telemetry and 2.400–2.4835 GHz for power-saving applications and midfield band (1.704–1.833 GHz) for seamless wireless power transfer (WPT). The antenna has a compact size of $7.5\times 10.5\times 0.127$ mm3, achieved through the utilization of meandered resonators. The use of meandered resonators also resulted in reduced coupling between the MIMO elements due to opposite flowing current cancellation. The presented MIMO antenna, optimized inside a realistic capsule with batteries, sensors, and electronic components, was fabricated and tested. Simulated and measured results in terms of S-parameters and radiation patterns correlated well with measured bandwidths of 90, 129, and 200 MHz and measured gains of −37.3, −30.3, and −27.9 dBi at 0.915, 1.780, and 2.450 GHz, respectively. Verification of the specific absorption rate (SAR) affirms that the suggested antenna is suitable for utilization within the human body. In addition, based on the link-budget analysis, it can be confirmed that the presented implantable MIMO antenna can establish a reliable communication link up to distances of 14, 9, and 6 m at 0.915, 1.780, and 2.450 GHz, respectively, for transferring high data rate (78 Mb/s) information. Moreover, an assessment of MIMO and diversity performance, specifically with regard to envelope correlation coefficient (ECC) and diversity gain (DG), was conducted, revealing results that fell within acceptable limits. To the authors’ best understanding, this marks the first four-port triple-band implantable MIMO antenna specifically designed for applications in WCE and deep tissue scenarios.

In this article, a water-based implantable antenna (WBIA), easily convertible into multiple-input multiple-output (MIMO) is introduced for medical implantable applications. The MIMO version of the WBIA is composed of two circular radiators apart by a small edge-to-edge gap of $0.018\lambda $ . The MIMO WBIA has a compact radius of 5 mm and a height of 4 mm which exhibits one of the miniaturized sizes previously reported for medical applications. This miniaturization is made possible by the very high permittivity of water and the capacitive effect between the WBIA ground plane and corresponding radiators. Both antennas provide complete control over the operating frequency by adjusting the height and radius of the water (antenna), allowing for customization to suit other desired frequencies. The radiators of both the MIMO antennas are radiating in opposite directions, thus also enabling radiation diversity. In a homogeneous phantom, the MIMO antenna exhibits a wider -10 dB bandwidth of 500 MHz, a higher gain of -18 dBi, and an isolation of 17 dB at 2.45 GHz. Because of the use of water and minimal metal without slots or vias, the proposed antennas exhibit significantly lower specific absorption rate (SAR) values compared to previously reported implantable antennas; therefore, the proposed antennas offer enhanced user safety benefits. Due to electrical properties comparable to human tissue, the proposed WBIAs smoothly transform the radiated energy; therefore, they provide very high radiation efficiencies compared to previously designed antennas. Apart from the aforementioned benefits, the proposed antennas are 3-D printable, thus offering much lower fabrication costs. To validate the performance of a complete system capable of performing biotelemetry, the antennas are integrated with capsule circuitry. The results measured in minced pork are found to be in close agreement with the simulation results. Due to frequency control, flexible functionality, high efficiency, lower SAR, pattern diversity (PD), and lower fabrication costs, the proposed antennas could be more beneficial for MIDs, especially for capsule endoscopes.

Smart textiles—fabrics integrated with electronics—have the potential to revolutionize e-healthcare applications by enabling sensing, communication, and interaction with the environment. This article focuses on developing a battery-free smart-textile-based energy harvester for powering Internet of Things (IoT)-enabled wearable sensors, with a particular emphasis on its application in e-healthcare. The energy harvester is digitally embroidered and can be easily integrated into textile products, including clothing. A multiport design was used, enabling it to harvest energy from multiple directions and convert it into electricity to power wearable sensors. A single element in the proposed multiport energy-harvesting array generates a beam with a peak gain of 7.25 dBi and approximately 68$^{\circ }$ half-power beamwidth, using a simplified and compact design owing to the absence of complicated feeding networks. The performance of the energy harvester was evaluated through simulations and experiments. Furthermore, the feasibility of integrating the proposed energy harvester into commercially available IoT sensor nodes was demonstrated using a wirelessly powered wearable device. The device was shown to provide real-time temperature and humidity data without external batteries. The use of smart textiles and energy-harvesting technology offers a self-sustaining solution for wearable devices, greatly enhancing their functionality and usability, particularly for e-healthcare applications.