https://scholar.dgist.ac.kr/handle/20.500.11750/1928 2026-09-26T00:07:53Z 2026-09-26T00:07:53Z Talaniuk, Viktoriia Mistewicz, Krystian Gawron, Anna Marcinkowski, Andrzej Szeluga, Urszula Myalska-Głowacka, Hanna Kaja, Kushal Ruthvik Hajra, Sugato Kim, Hoe Joon Godzierz, Marcin https://scholar.dgist.ac.kr/handle/20.500.11750/60871 2026-09-23T05:40:13Z 2026-04-30T15:00:00Z

Title: Exploring the potential of multifunctional MWCNT/PDMS nanocomposites in thermal and mechanical energy harvesting Author(s): Talaniuk, Viktoriia; Mistewicz, Krystian; Gawron, Anna; Marcinkowski, Andrzej; Szeluga, Urszula; Myalska-Głowacka, Hanna; Kaja, Kushal Ruthvik; Hajra, Sugato; Kim, Hoe Joon; Godzierz, Marcin Abstract: In this work, it was shown that a nanocomposite of multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) is a versatile material that can convert both thermal and mechanical energy into electrical energy. The MWCNT/PDMS nanocomposite with a MWCNT concertation of 2 mass% was chemically etched to expose the carbon nanotubes on the surface of the nanocomposite. This resulted in a significant reduction in contact resistance, an increase in electrical conductivity, and consequently, an improvement in thermoelectric properties. For the first time, the MWCNT/PDMS nanocomposite was thoroughly analyzed to characterize its thermoelectric and triboelectric properties. Electrical conductivity, specific heat, thermal diffusivity, and thermal conductivity were investigated as a function of temperature in a wide range from 298 to 373 K. The optimized characteristics of the MWCNT/PDMS nanocomposite were achieved due to its relatively high electrical conductivity (22 S cm(-1)) and low thermal conductivity (0.22 W m(-1) K-1). The Seebeck coefficient and thermoelectric efficiency factor were found to increase with temperature, reaching the maximum values of 4.6 mu V K-1 and 7.4 & centerdot;10(-5), respectively. The MWCNT/PDMS nanocomposite was used as a negative friction layer in a triboelectric nanogenerator (TENG). This device operated in contact-disconection mode, generating an output voltage of 7 V and a current of 113 nA. During long-term testing, the TENG demonstrated exceptional stability and repeatability of its voltage response. It was shown that the MWCNT/PDMS-based TENG is suitable for harvesting mechanical energy from human body movements, such as finger tapping, foot tapping, and hammering. The developed MWCNT/PDMS nanocomposite shows great potential for use in flexible wearable sensors for self-powered temperature monitoring and motion detection.

2026-04-30T15:00:00Z Kumar, Naveen Kaja, Kushal Ruthvik Panda Swati Hajra Sugato Belal, Mohamed Ahmed Bhosale, Premkumar Sharad Khanapuram, Uday Kumar Rajaboina, Rakesh Kumar Keum, Hohyun Lee, Kyoungtae Kim, Hoe Joon https://scholar.dgist.ac.kr/handle/20.500.11750/60870 2026-09-23T06:40:16Z 2026-05-31T15:00:00Z

Title: Self-poled and poling-free efficient piezoelectric nanogenerators for power generation and self-powered applications Author(s): Kumar, Naveen; Kaja, Kushal Ruthvik; Panda Swati; Hajra Sugato; Belal, Mohamed Ahmed; Bhosale, Premkumar Sharad; Khanapuram, Uday Kumar; Rajaboina, Rakesh Kumar; Keum, Hohyun; Lee, Kyoungtae; Kim, Hoe Joon Abstract: Piezoelectric nanogenerators (PENGs) have emerged as promising energy harvesters capable of converting waste mechanical energy into usable electrical power for self-powered electronic applications. Traditionally, PENGs require an external poling process to align ferroelectric dipoles and achieve efficient operation. However, reliance on high-voltage poling, time-consuming processing, and potential material degradation limits the scalability and practicality of conventional PENGs. Recent research has therefore focused on developing self-poled, polingfree PENGs that offer intrinsic polarization, enhanced stability, and simplified fabrication without external treatments. This review summarizes the fundamental working principles of PENGs and the effect of polarization on their performance. Then, an in-depth discussion of the concept and comparison between the self-poling and poling-free mechanisms is provided. Recent advances in self-poled or poling-free PENGs, material innovations, including polymers, ceramics, and composites, as well as device engineering strategies that enable efficient energy conversion without external poling, are also demonstrated. The review concludes with significant challenges, including material durability, large-scale fabrication, and integration into complex systems, as well as future research prospects for developing next-generation self-powered technology. By integrating current advances and highlighting key obstacles, the review attempts to offer valuable insights into the future development of efficient, scalable, and environmentally sustainable poling-free PENGs. To the best of our knowledge, this is the first comprehensive review of self-poled and poling-free PENGs, focusing on underlying mechanisms, material fabrication methods, and emerging applications.

2026-05-31T15:00:00Z Ramu, Dandugudumula Hajra, Sugato Panda, Swati Kaja, Kushal Ruthvik Mishra, Yogendra Kumar Kim, Hoe Joon Kim, Eunjoo https://scholar.dgist.ac.kr/handle/20.500.11750/60674 2026-08-25T07:10:18Z 2026-06-30T15:00:00Z

Title: TENG-Driven Electrotherapy: A Self-Powered Approach to Inducing Cancer Cell Apoptosis Author(s): Ramu, Dandugudumula; Hajra, Sugato; Panda, Swati; Kaja, Kushal Ruthvik; Mishra, Yogendra Kumar; Kim, Hoe Joon; Kim, Eunjoo Abstract: Most of the cancer-related deaths are caused by metastasis, which also remains a significant obstacle to successful clinical management. Even though several anti-metastatic treatments have been put forth, systemic toxicity, low cellular responsiveness, and drug resistance typically undermine their therapeutic efficacy. Although triboelectric nanogenerators (TENGs) have become highly effective self-powered electrical therapies for biomedical applications, their potential as an active treatment tool for metastasis suppression has not yet been fully investigated. Here, we present a self-powered TENG-driven electrotherapeutic approach that suppresses early lung cancer cell migration in vitro by carefully regulated electrical stimulation. Electrical stimulation at 60 V and 760 nA for 5 min disrupted redox homeostasis and induced caspase-3-mediated apoptotic death of A549 cells. TENG-based electrical therapy serves as a self-powered electrical stimulation source that triggers apoptosis in cancer cells by activating the caspase-3/PARP pathway. These results raise possibilities for TENGs not merely as energy-harvesting devices but as active, mechanistic electrotherapeutic platforms, converting mechanical energy into controlled electrical signals that initiate apoptotic cell death pathways in cancer cells.

2026-06-30T15:00:00Z Ukasi, Sirinya Hajra, Sugato Kim, Hoe Joon Sriphan, Saichon Pongampai, Satana Charoonsuk, Thitirat Vittayakorn, Naratip https://scholar.dgist.ac.kr/handle/20.500.11750/60669 2026-08-21T06:40:12Z 2026-07-31T15:00:00Z

Title: Flexible and Self-Powered Wearable Sensors for Tremor Monitoring in Parkinson'S Disease: Recent Advances in Materials and Device Architectures Author(s): Ukasi, Sirinya; Hajra, Sugato; Kim, Hoe Joon; Sriphan, Saichon; Pongampai, Satana; Charoonsuk, Thitirat; Vittayakorn, Naratip Abstract: Parkinson’s disease (PD) is a progressive neurodegenerative disorder where tremor remains one of the most prominent anddisabling motor symptoms. Traditional clinical rating scales for disease severity rely on clinician observation and patient self-report, often failing to capture the dynamic and continuous nature of tremors in daily life. This drives the development of objectivemonitoring technologies, such as wearable sensors, for more accurate evaluation of PD severity. However, many existing systemsuse rigid materials that lack the mechanical compliance and skin conformability required for stable biointegration. This reviewsummarizes advances in flexible wearable sensors for PD tremor assessment from material innovations to a device engineeringperspective, covering inertial measurement units (IMUs), electromyography (EMG), and emerging self-powered systems such astriboelectric (TENG) and piezoelectric nanogenerators (PENG). This review highlightshow functional materials, microstructuraldesign, and device architectures govern sensing mechanisms and performance, with particular emphasis on the transition fromrigid components to soft, skin-interfaced technologies. Recent patent activity reflects a shift toward multimodal, wireless, andclinically integrated platforms. Despite progress, challenges remain, including motion artifacts, durability, and limited large-scale clinical validation. Integration of flexible materials, self-powered designs, and AI-driven analytics enables continuous,personalized monitoring, moving closer to real-world clinical deployment and improved patient care.

2026-07-31T15:00:00Z