“…Fig. 19.Structures of the fractal antennas (a) pentagonal-shaped fractal micro strip patch antenna (MPA) [19], (b) Minkwoski fractal antenna on FR-4 [20] and (c) Minkwoski fractal antenna on LCP [21]. …”
Section: Antenna Architecturesmentioning
confidence: 99%
“…Various types of fractals are being used for this purpose, like-Minkwoski, Hilbert curve type, etc. [20,21,31]. A10 × 10 mm 2 fractal UWB omni-directional microstrip patch antenna (MPA) which is pentagonal in structure with star-shaped slots inside the patch was proposed by Nizar Hammed et al [19].…”
This review paper explores the potential use of the planar miniaturized antenna for wireless capsule endoscopy application: one of the promising fields in the current era. The paper highlights the design strategy, various optimization techniques with respect to system realization, material compatibility issues and finally the mandatory EM radiation effect analysis for the said application. It compares amongst various currently reported structures in context with different performance metrics. Inherent challenges of this emerging field of bio-medical engineering have also been detailed here along with futuristic approaches for enhancing the throughput.
“…Fig. 19.Structures of the fractal antennas (a) pentagonal-shaped fractal micro strip patch antenna (MPA) [19], (b) Minkwoski fractal antenna on FR-4 [20] and (c) Minkwoski fractal antenna on LCP [21]. …”
Section: Antenna Architecturesmentioning
confidence: 99%
“…Various types of fractals are being used for this purpose, like-Minkwoski, Hilbert curve type, etc. [20,21,31]. A10 × 10 mm 2 fractal UWB omni-directional microstrip patch antenna (MPA) which is pentagonal in structure with star-shaped slots inside the patch was proposed by Nizar Hammed et al [19].…”
This review paper explores the potential use of the planar miniaturized antenna for wireless capsule endoscopy application: one of the promising fields in the current era. The paper highlights the design strategy, various optimization techniques with respect to system realization, material compatibility issues and finally the mandatory EM radiation effect analysis for the said application. It compares amongst various currently reported structures in context with different performance metrics. Inherent challenges of this emerging field of bio-medical engineering have also been detailed here along with futuristic approaches for enhancing the throughput.
“…On the way to this current development scenario of ESAs, implementing the standard micro-fabrication process electrical modeling prior to the fabrication process will be very much beneficial for any antenna engineers; it will give an overview of the working principle of the radiating element. Usually, for miniaturization of antenna structures seven basic methods are adopted in designing, such as: meandering [11], looping [12], fractals [13][14][15], shorting pin [16], loading of reactive elements [17,18], slot incorporation [19,20] and stacking (or capacitive loading) [21,22]. One or more of these techniques can be adopted to realize an efficient small antenna as per the user specifications.…”
This work outlines various electrically small antennas' design and development activities for biomedical applications. It also covers the electrical modeling aspects of all these miniaturized antennas. Three antennas with different specifications have been discussed with diversified proposed applications. The first example deals with a single frequency (9.45 GHz) on-chip antenna. In contrast, the second one covers an ultra-wideband frequency range (2.5 to 20.6 GHz), and finally, the third antenna targets an application for a 100 GHz band. The size of the first one is 2×2.1 mm2, while the second on-chip antenna occupies an area of about 4.6 ×11.5 mm2 over the silicon substrate. The third antenna module is developed on LCP substrate, which can be accommodated within a 12.5×27 mm2 area. Though the two on-chip antennas offer the only lower gain of around -29 dBi and -3 dBi, respectively, implementing silicon as a base material paves the way for monolithic integration within a chip. The third candidate exhibits a directive gain of 19-20 dBi with a radiation efficiency of 80% over the 100 GHz band. The highlighted portion of this current research work is to propose empirical modeling of electrically small antennas. The proposed methods claim to be most straightforward in nature. Without applying complicated mathematical jugglery, accessible circuit models are presented for these aforesaid antennas, going to the insight of device physics. A comparative study has been carried out with the proposed model and fullwave simulated results for each antenna to validate the circuit models.
“…With recent advances, they can now obtain key diagnostic information about the chemical and/or biomolecular compositions, such as intestinal gas profiles related to gut microbial fermentative activities, biomarkers of thiosulfate and acyl-homoserine lactone, and GI bleeding . By integrating them with medicines, the electromagnetic field generated from them can monitor medication adherence. , In addition, drug release at intended positions can be monitored with a pH-triggered switch or by inserting ingestible tips into the stomach lining in a drug delivery system. , To achieve safe sensing with less attenuation, radio frequencies of 420–450 MHz (IEEE 802.15.6 standard), 433 MHz (accepted by FDA), and 900 MHz are commonly used for medical devices. − As a simple and costless method that does not necessarily require a power supply, devices operating at 13.56 MHz are also attracting attention. , Although they can transmit unique in-body data, some devices for patients with bowel disease showed 1.4% retention in the GI tract due to their size and required surgery for removal. To improve the safety, changes in materials are required, and the development of completely new devices consisting of edible electronic components is eagerly anticipated. − …”
Ingestible
electronic devices are tools for exploring the condition
of the gastrointestinal tract and adjacent organs without a burden
on the patients. Making them safe requires that they be fabricated
with harmless materials. In this study, we developed a capacitor using
food materials for a wireless sensing component. As a safer approach,
gelatin, an ingredient responsive to external stimuli, was selected
as a substrate for deforming the device at the desired time. Gelatin
experiences sol–gel changes near body temperature; however,
it is instantly dissolved and is not suitable for long-term use in
the body. Thus, to maintain its thermal responsiveness, we used a
tangle of gel networks created by mixing gelatin and chitosan without
cross-linking agents. Our search for the appropriate gel mixing ratio
provided insights into the criteria for achieving slow sol–gel
changes and how to improve the thermal durability. We transferred
a sputtered gold film onto the gel films to produce electrodes and
then made a capacitor by sandwiching a naturally dried sodium polyacrylate
film between the electrodes. The resonance frequency measurement of
RLC circuits in combination with commercial plane coils showed that
the capacitor worked in the megahertz band and that it collapsed when
immersed in hot water. Gastric acid detection was also achieved with
this capacitor. This electronic part will contribute to the development
of implanted or ingestible medical devices and a wide range of environmental
sensors composed of natural ingredients.
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