Browsing by Author "Mirzajani, Hadi"

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Citation Count: 0
Continuous Glycemic Monitoring Enabled by A Wi-Fi Energy-Harvesting Wearable Sweat-Sensing Patch
(Wiley, 2024) Istıf, Emın; Abbasiasl, Taher; Mirzajani, Hadi; Istif, Emin; Akhtar, Muhammad Junaid; Cakir, Cengiz; Beker, Levent
Continuous monitoring of multiple physiological parameters, such as glucose levels, temperature, and heart rate variability (HRV) is crucial for effective diabetes management and mitigating the risks associated with hypoglycemic events. These events often occur without apparent symptoms, posing a challenge for diabetic patients in managing their condition. Therefore, a non-invasive wearable device capable of continuously measuring multiple body signals to predict hypoglycemic events would be highly beneficial. In this study, a wearable patch that continuously measures glucose, temperature, and HRV is presented. The device uses a novel power harvesting system to convert radiofrequency (RF) signals with the frequency of 2.45 GHz to direct current (DC) signals to extend the battery life for further continuous monitoring. The patch is small and has a conformal structure that can easily fit onto different body parts. The screen-printed glucose sensor demonstrates a sensitivity of 10.3 nA cm-2 mu M-1, a limit of detection (LOD) of 8.9 mu M, and a limit of quantification (LOQ) of 27 mu M. The device employs a photoplethysmography (PPG) module with a peak-finding algorithm to calculate the HRV values. In vivo experiments demonstrate the validation of the device's proper operation in glucose, HRV, and temperature measurement. This study introduces a wearable patch for diabetes management, employing a unique Wi-Fi energy harvesting system for extended battery life. The device's conformal structure enables effortless placement on the body, providing continuous monitoring of glucose, HRV, and temperature. The platform presents a non-invasive physiological monitoring approach that enhances diabetes care by offering real-time data in a compact and efficient design. image
Citation Count: 12
Miniaturized wireless sensor enables real-time monitoring of food spoilage
(Nature Portfolio, 2023) Istıf, Emın; Mirzajani, Hadi; Dag, Cagdas; Mirlou, Fariborz; Ozuaciksoz, Elif Yaren; Cakir, Cengiz; Koydemir, Hatice Ceylan
Food spoilage results in food waste and food-borne diseases. Yet, standard laboratory tests to determine spoilage (mainly volatile biogenic amines) are not performed regularly by supply chain personnel or end customers. Here we developed a poly(styrene-co-maleic anhydride)-based, miniature (2 x 2 cm(2)) sensor for on-demand spoilage analysis via mobile phones. To demonstrate a real-life application, the wireless sensor was embedded into packaged chicken and beef; consecutive readings from meat samples using the sensor under various storage conditions enabled the monitoring of spoilage. While samples stored at room temperature showed an almost 700% change in sensor response on the third day, those stored in the freezer resulted in an insignificant change in sensor output. The proposed low-cost, miniature wireless sensor nodes can be integrated into packaged foods, helping consumers and suppliers detect spoilage of protein-rich foods on demand, and ultimately preventing food waste and food-borne diseases. Standard tests to determine food spoilage are costly and time consuming. A poly(styrene-co-maleic anhydride)-based sensor offers a low-cost alternative that can be linked to mobile phones for real-time spoilage analysis. The device was tested on chicken and beef samples under various storage conditions.
Citation Count: 19
Photolithography-Based Microfabrication of Biodegradable Flexible and Stretchable Sensors
(Wiley-V C H Verlag Gmbh, 2023) Istıf, Emın; Singh, Rahul; Mirzajani, Hadi; Istif, Emin; Akhtar, Muhammad Junaid; Abbasiasl, Taher; Beker, Levent
Biodegradable sensors based on integrating conductive layers with polymeric materials in flexible and stretchable forms have been established. However, the lack of a generalized microfabrication method results in large-sized, low spatial density, and low device yield compared to the silicon-based devices manufactured via batch-compatible microfabrication processes. Here, a batch fabrication-compatible photolithography-based microfabrication approach for biodegradable and highly miniaturized essential sensor components is presented on flexible and stretchable substrates. Up to 1600 devices are fabricated within a 1 cm(2) footprint and then the functionality of various biodegradable passive electrical components, mechanical sensors, and chemical sensors is demonstrated on flexible and stretchable substrates. The results are highly repeatable and consistent, proving the proposed method's high device yield and high-density potential. This simple, innovative, and robust fabrication recipe allows complete freedom over the applicability of various biodegradable materials with different properties toward the unique application of interests. The process offers a route to utilize standard micro-fabrication procedures toward scalable fabrication of highly miniaturized flexible and stretchable transient sensors and electronics.
Citation Count: 2
A Wearable Touch-Activated Device Integrated with Hollow Microneedles for Continuous Sampling and Sensing of Dermal Interstitial Fluid
(Wiley-v C H verlag Gmbh, 2023) Istıf, Emın; Mirlou, Fariborz; Mirzajani, Hadi; Bathaei, Mohammad Javad; Istif, Emin; Shomalizadeh, Narges; Beker, Levent
Dermal interstitial fluid (ISF) is emerging as a rich source of biomarkers that complements conventional biofluids such as blood and urine. However, the impact of ISF sampling in clinical applications has been limited owing to the challenges associated with extraction. The implementation of microneedle-based wearable devices that can extract dermal ISF in a pain-free and easy-to-use manner has attracted growing attention in recent years. Here, a fully integrated touch-activated wearable device based on a laser-drilled hollow microneedle (HMN) patch for continuous sampling and sensing of dermal ISF is introduced. The developed platform can produce and maintain the required vacuum pressure (as low as approximate to -53 kPa) to collect adequate volumes of ISF (approximate to 2 mu L needle-1 h-1) for medical applications. The vacuum system can be activated through a one-touch finger operation. A parametric study is performed to investigate the effect of microneedle array size, vacuum pressure, and extraction duration on collected ISF. The capability of the proposed platform for continuous health monitoring is further demonstrated by the electrochemical detection of glucose and pH levels of ISF in animal models. This HMN-based system provides an alternative tool to the existing invasive techniques for ISF collection and sensing for medical diagnosis and treatment. A fully-integrated touch-activated wearable device is developed for continuous sampling and electrochemical analysis of interstitial fluid. The elastic self-recovery of the vacuum generation system enables a wide range of negative pressures and extraction rates. The developed device can successfully detect glucose and pH levels and holds the potential for continuous sensing of multiple biomarkers in extracted interstitial fluid.image
Citation Count: 1
A Wearable Touch-Activated Device Integrated with Hollow Microneedles for Continuous Sampling and Sensing of Dermal Interstitial Fluid (Adv. Mater. 2/2024)
(Wiley-v C H verlag Gmbh, 2024) Istıf, Emın; Mirlou, Fariborz; Mirzajani, Hadi; Bathaei, Mohammad Javad; Istif, Emin; Shomalizadeh, Narges; Beker, Levent
[No Abstract Available]