Browsing by Author "Chu, Hou-Jen"

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A NOVEL NANOELECTROMAGNETIC SYSTEM USING MULTIFERROIC/MAGNETOELECTRIC NI-NANO-CHEVRON/PMN-PT HETEROSTRUCTURE TO DEMONSTRATE AN ELECTRIC -FIELD -CONTROLLED PERMANENT MAGNETIC SINGLE -DOMAIN TRANSFORMATION
(2018-01-01)
Cheng, Chih-Cheng
;
Lin, Shin-Hung
;
Chen, Yu-Jen
;
Wang, Hsin-Min
;
Chu, Hou-Jen
In this paper, we report a novel nanoelectromagnetic system using multiferroic/magnetoelectric Ni-nanochevron/PMN-PT heterostructure to demonstrate an electric field -controlled permanent magnetic single-domain transformation. The heterostructure consists of a magnetostrictive Ni-nano-chevron, Pt top and bottom electrodes, and a piezoelectric PMN-PT substrate. In initial state (as demagnetized), the magnetization of the magnetic single domain is stably along the long axis of the nano-chevron. A magnetic field of 3000 Oe (along 45 degree of nano-chevron) is applied to magnetize the Ni-nano-chevron from stable single domain to metastable two-domains. After this, an electric field of 0.8MV/m is applied to the PMN-PT substrate to produce the converse magnetoelectric effect to transform the two-domains. After the electric field is removed, the two-domains are further transformed back to the single-domain. Finally, when comparing the domains before and after applying our approach, approximately 50 % of single-domains are successfully and permanently switched (i.e., magnetization-direction is permanently rotated 180 degrees).
An Electromagnetic-Induction Approach for Screw-Hole Targeting in Interlocking-Nail Surgery
(2012)
Chung, Tien-Kan
;
Chu, Hou-Jen
;
Wong, Tze-Hong
;
Hsu, Wensyang
;
Lee, Meng-Shiue
We report a novel approach for targeting screw-holes of an intramedullary nail in a long-bone fracture surgery. The approach utilizes the electromagnetic induction to avoid over exposure of radioactivity which is the critical issue in conventional X-ray-imaging targeting method. Based on the approach, we fabricate a targeting system. The targeting system consists of a c-shaped electromagnet, detecting-coil, guiding-mechanism, and measurement electronics. When a voltage is applied to the electromagnet, magnetic flux is generated in the air gap of the electromagnet and subsequently detected by the coil. When the flux is detected by the coil, a voltage response is induced in the coil. When a nail in a bone is scanned through the air gap of the electromagnet, the flux is influenced due to a discrepancy of the permeability between the location with and without the hole of the nail. The influenced flux induces different voltage response in the coil. Through analyzing the voltage response, we establish a criterion for targeting the holes. By the criterion, the experimental result shows the maximum error of targeting a hole with a diameter of 5 mm is less than 2.5 mm.
ELECTRICAL CONTROL OF MAGNETIC MULTI-DOMAIN TRANSFORMATION IN A SPECIFIC GEOMETRIC-PATTERNED NI NANOSTRUCTURE ON A PIEZOELECTRIC [PB(MG(1/3)NB(2/3))O3](0.68)-[PBTIO3](0.32) SUBSTRATE
(2016)
Chen, Yu-Jen
;
Chung, Tien-Kan
;
Lin, Po-Jung
;
Hung, Chiao-Fang
;
Chu, Hou-Jen
In this paper, we report an electrical control of magnetic multi-domain-walls transformation in an N-shape-patterned Ni nanostructures on a piezoelectric [Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) substrate. Based on the converse-magnetoelectric-effect induced domain-wall transformation and the specific N-shape geometry guided domain-wall motion, the domain walls are successfully transformed by an applied electric field of 0.8 MV/m from the transverse domain wall state into the flux closure vortex domain state. These experimental results achieve the electrical control of multi-domain-walls transformation and would create more data storage and memory applications in the future.
Electromagnetic Coil/Inductance-Based Nondestructive Methods for Locating Distal Screw-Holes of an Intramedullary Interlocking-Nail
(2013)
Chung, Tien-Kan
;
Chu, Hou-Jen
;
Wong, Tze-Hong
;
Cheng, Ya-Wen
;
Hsu, Wensyang
We report an electromagnetic inductance/coil-based non-destructive method to target distal screw-holes in an intramedullary interlocking-nail surgical operation for fixing a long-bone fracture. The method is a radiation-free approach addressing the over-exposure issue of radioactivity caused by the typical X-ray-imaging approach. According to the method, we fabricate a targeting-system consisting of an internal inductance, external coil, guiding-mechanism, and driving/measurement electronics. When a voltage is applied to the internal inductance embedded in one of the distal screw-holes of a nail inserted in a bone, a directional magnetic flux is generated by the internal inductance due to the electromagnetic induction. Subsequently, the directional magnetic flux penetrates the nail and bone. When the external coil outside the bone scans along the axial and angular directions of the nail/bone, different amount of the generated magnetic flux is detected by the coil and consequently corresponding voltage response is induced in the coil due to the electromagnetic induction. In contrast to the magnetic flux generated and detected by the inductance and coil, respectively, we also investigate the reverse physics-behavior of the flux transmission (i.e., flux generated and detected by the coil and inductance) in order to improve the approach. Finally, by correlating the induced-voltage responses with the scanned axial-locations along the nail/bone, correlation curves are plotted. Through analyzing the curves, a criterion for predicting the location of the screw-holes of the nail is established. When compared the predicted location with the actual location of the screw-hole, the maximum targeting error is 2 mm for locating a screw-hole with a diameter of 5 mm. The result shows the targeting-method is accurate, fast, and easy for the surgeons and significantly simplifies the existed interlocking-nail surgical procedures.
Electromagnetic/Magnetic-Coupled Targeting System for Screw-Hole Locating in Intramedullary Interlocking-Nail Surgery
(2014-12-01)
Wong, Tze-Hong
;
Chung, Tien-Kan
;
Liu, Tzu-Wei
;
Chu, Hou-Jen
;
Hsu, Wensyang
At present, intramedullary interlocking nails are widely used for bone-fracture fixation in orthopedic surgeries. Surgeons often use X-ray imaging to find the actual location of the distal screw-holes of the nail after the nail is inserted into the medullary canal of a bone for fixation. Thus, the patients and medical team are inevitably exposed to radioactivity. In this paper, we report a radiation-free electromagnetic/magnetic-coupled targeting system to locate the distal screw-holes of the nail used in interlocking-nail surgery. The targeting system consists of a c-shaped electromagnet with a pick-up coil, a highly permeable curved silicon-steel strip embedded on the nail, a guiding mechanism, and electronic measuring instruments. An alternative current is applied to the electromagnet to generate a uniform magnetic field/flux in the electromagnet\'s air gap. When the nail inserted into the medullary canal of a bone is scanned through or rotated in the air gap of the electromagnet, the magnetic flux in the air gap is influenced by the silicon-steel strip embedded on the nail. The variation of the magnetic flux induces a voltage response in the pick-up coil due to electromagnetic induction. The pattern of the voltage response is analyzed to establish a criterion for screw-hole targeting. The results obtained using this criterion reveal that the maximum targeting error of the location and orientation targeting for a screw-hole with a diameter of 5 mm is <2 mm and 10 degrees, respectively. Thus, the system/approach is sufficiently simple and accurate to be used by surgeons in clinical surgery.
Magnetic-field-assisted electric-field-controlled rotation of magnetic stripe domains in a magnetoelectric Ni microbar/[Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) heterostructure
(2016-04)
Chung, Tien-Kan
;
Wang, Hsin-Min
;
Chen, Yu-Jen
;
Lin, Shin-Hung
;
Chu, Hou-Jen
We report a magnetic-field-assisted electric-field-controlled approach to rotate magnetic stripe domains in a magnetoelectric Ni-microbar/[Pb(Mg1/3Nb2/3)O-3](0.68)-[PbTiO3](0.32) heterostructure. A magnetic field is applied for magnetizing the microbar\'s stripe domains along the microbar\'s short/magnetic-hard axis. Subsequently, an electric field is applied for induction of a transformation of domains through the converse magnetoelectric effect. Owing to the microbar\'s geometry, the transformation causes the stripe domains to rotate away from the short/magnetichard axis toward the long/magnetic-easy axis. The rotation angle increases in proportion to the increasing electric field intensity. A maximal rotation of 90 degrees is obtained at the electric field intensity of 0.8MV/m. The rotation state persists after removing the electric field. (C) 2016 The Japan Society of Applied Physics
Self-Magnetization-Switchable Micro-Magnetic Track Based Magnetic-Bead Manipulation
(2018-01-01)
Chung, Tien-Kan
;
Fang, Lin-Huei
;
Liu, Tzu-Wei
;
Chu, Hou-Jen
;
Ranabotu, Jaganmohan Reddy
In this paper, we report a self-magnetizationswitchable magnetic-track based magnetic-bead manipulation on a silicon wafer. The manipulation approach consists of a thermomagnetic NiCu micro-disc track (which is deposited on the silicon wafer), micro magnetic bead, a thermoelectric generator (TEG; which is placed beneath the silicon wafer), and four external electromagnets (which are used to produce a directional magnetic field). The Curie temperature of the NiCu micro-disc track is approximate room temperature. Due to this, when the TEG cools the NiCu micro-disc track lower than its Curie temperature (i.e., lower than room temperature), the track becomes ferromagnetic. However, when the TEG heats the NiCu micro-disc track higher than its Curie temperature (i.e., about or higher than room temperature), the track becomes paramagnetic. Therefore, by alternative cooling and heating, the track is switched between ferromagnetic and paramagnetic (i.e., magnetic moment is changed between normal and very small). This achieves on-chip self-magnetization-switchable track. Furthermore, when a directional magnetic field is applied to the track which becomes ferromagnetic, the track can guide the bead manipulation. Alternatively, when the track becomes paramagnetic, the track cannot guide the bead manipulation. This novel selfmagnetization-switchable magnetic-track-guided bead manipulation provides an important alternative bead manipulation for biomedical NIEMS/NEMS systems.