NTI Research
Permanent URI for this collectionhttps://hdl.handle.net/10735.1/3658
Browse
Browsing NTI Research by Author "0000-0001-5845-5137 (Baughman, RH)"
Now showing 1 - 5 of 5
- Results Per Page
- Sort Options
Item Enhancement of Electromagnetic Interference Shielding Effectiveness with Alignment of Spinnable Multiwalled Carbon Nanotubes(Pergamon-Elsevier Science Ltd, 2018-10-23) Lee, Duck Weon; Park, Jongwoo; Kim, Bum Joon; Kim, Hyunsoo; Choi, Changsoon; Baughman, Ray H.; Kim, Seon Jeong; Kim, Youn Tae; 0000-0001-5845-5137 (Baughman, RH); Baughman, Ray H.This research develops a unique material to attenuate electromagnetic interference (EMI) by using spinnable multiwalled carbon nanotubes (MWNTs) combined with bio-polydimethylsiloxane (PDMS) that contains BaTiO₃ (MBPBT). In particular, a plaid pattern, formed by the spinnable MWNTs, is very effective in attenuating the propagation of EM waves, which achieves over 20 dB at 8.2-12.4 GHz (X-band frequency range). This means that a filter type of the spinnable MWNTs is actively able to handle the directionality and movement of EMI propagation. In addition, the MBPBT is characterized by its strong mechanical advantage (bending radius 180 degrees).Item Harvesting Electrical Energy from Torsional Thermal Actuation Driven by Natural Convection(Nature Publishing Group) Kim, Shi Hyeong; Sim, Hyeon Jun; Hyeon, Jae Sang; Suh, Dongseok; Spinks, Geoffrey M.; Baughman, Ray H.; Kim, Seon Jeong; 0000-0001-5845-5137 (Baughman, RH); Baughman, Ray H.; Kim, Seon JeongThe development of practical, cost-effective systems for the conversion of low-grade waste heat to electrical energy is an important area of renewable energy research. We here demonstrate a thermal energy harvester that is driven by the small temperature fluctuations provided by natural convection. This harvester uses coiled yarn artificial muscles, comprising well-aligned shape memory polyurethane (SMPU) microfibers, to convert thermal energy to torsional mechanical energy, which is then electromagnetically converted to electrical energy. Temperature fluctuations in a yarn muscle, having a maximum hot-to- cold temperature difference of about 13 ⁰C, were used to spin a magnetic rotor to a peak torsional rotation speed of 3,000 rpm. The electromagnetic energy generator converted the torsional energy to electrical energy, thereby producing an oscillating output voltage of up to 0.81 V and peak power of 4 W/kg, based on SMPU mass.Item High-Performance Biscrolled MXene/Carbon Nanotube Yarn Supercapacitors(Wiley-VCH Verlag) Wang, Z.; Qin, S.; Seyedin, S.; Zhang, J.; Wang, J.; Levitt, A.; Li, Na; Haines, Carter; Ovalle-Robles, R.; Lei, W.; Gogotsi, Y.; Baughman, Ray H.; Razal, J. M.; 0000 0003 5232 4253 (Baughman, RH); 0000-0001-5845-5137 (Baughman, RH); Li, Na; Haines, Carter; Baughman, Ray H.Yarn-shaped supercapacitors (YSCs) once integrated into fabrics provide promising energy storage solutions to the increasing demand of wearable and portable electronics. In such device format, however, it is a challenge to achieve outstanding electrochemical performance without compromising flexibility. Here, MXene-based YSCs that exhibit both flexibility and superior energy storage performance by employing a biscrolling approach to create flexible yarns from highly delaminated and pseudocapacitive MXene sheets that are trapped within helical yarn corridors are reported. With specific capacitance and energy and power densities values exceeding those reported for any YSCs, this work illustrates that biscrolled MXene yarns can potentially provide the conformal energy solution for powering electronics beyond just the form factor of flexible YSCs.Item Magnetic Torsional Actuation of Carbon Nanotube Yarn Artificial Muscle(Royal Society of Chemistry) Lee, D. W.; Kim, S. H.; Kozlov, Mikhail E.; Lepró, Xavier; Baughman, Ray H.; Kim, S. J.; 0000 0003 5232 4253 (Baughman, RH); 0000-0002-0166-3127 (Lepró, X); 0000-0001-5845-5137 (Baughman, RH); Kozlov, Mikhail E.; Lepró, Xavier; Baughman, Ray H.Magnetically driven torsional actuation of a multiwalled carbon nanotube (MWNT) yarn was realized by first biscrolling NdFeB magnetic particles into helical yarn corridors to make a magnetic MWNT yarn. The actuating device comprised a pristineMWNT yarn that was connected to the magnetic MWNT yarn, with a paddle attached between these yarns. The application of a magnetic field reversibly drove torsional actuation of up to 80° within ∼0.67 seconds. This magnetic actuator was remotely powered, and its actuation stroke was the same when the muscle array was at 20 °C and at -100 °C.Item Orthogonal Pattern of Spinnable Multiwall Carbon Nanotubes for Electromagnetic Interference Shielding Effectiveness(Elsevier Ltd, 2019-05-022) Lee, D. W.; Kim, H.; Moon, J. H.; Jeong, J. -H; Sim, H. J.; Kim, B. J.; Hyeon, J. S.; Baughman, Ray H.; Kim, S. J.; 0000-0001-5845-5137 (Baughman, RH); Baughman, Ray H.The need for thin and lightweight electromagnetic interference shielding materials is rapidly increasing in several industries, such as aerospace and telecommunication. This research finds that a shielding material, which is developed by the orthogonal pattern of spinnable multiwall carbon nanotubes (MWNTs), is ultra-light weight, thin, and has a high shielding effectiveness (SE). An orthogonal pattern, generated by just alignment of the spinnable MWNTs without adding any support materials such as polymers, ceramics, and magnets demonstrates that it is possible to efficiently attenuate electromagnetic interference (EMI) in the X-band frequency range (8.2–12.4 GHz). EMI SE in the developed shielding material is about 19.2 dB with a specific shielding effectiveness (SSE)/t (thickness) value of 73,633 dB cm² g⁻¹ at a thickness of about 4.48 μm. In addition, absorption effectiveness in this shielding material is as high as 96.3%, which provides excellent ability to reduce the secondary damage by reflection. ©2019 Elsevier Ltd