Browsing by Author "Chen, Chin-Chung"

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A magnetic-piezoelectric smart material-structure sensing three axis DC and AC magnetic-fields
(2017-12-01)
Hung, Chiao-Fang
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Chen, Chin-Chung
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Yeh, Po-Chen
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Chen, Po-Wen
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Chung, Tien-Kan
In this paper, we demonstrate a smart material-structure can sense not only three-axis AC magnetic-fields but also three-axis DC magnetic-fields. Under x-axis and z-axis AC magnetic field ranging from 0.2 to 3.2 gauss, sensing sensitivity of the smart material-structure stimulated at resonant frequency is approximate 8.79 and 2.80 mV/gauss, respectively. In addition, under x-axis and z-axis DC magnetic fields ranging from 2 to 12 gauss, the sensitivity of the smart material-structure is 1.24-1.54 and 1.25-1.41 mV/gauss, respectively. In addition, under x-axis and z-axis DC magnetic fields ranging from 12 to 20 gauss, the sensitivity of the smart material-structure is 5.17-6.2 and 3.97-4.57 mV/gauss, respectively. These experimental results show that the smart material-structure successfully achieves three-axis DC and AC magnetic sensing as we designed. Furthermore, we also compare the results of the AC and DC magnetic-field sensing to investigate discrepancies. Finally, when applying composite magnetic-fields to the smart material-structure, the smart material-structure shows decent outputs as expected (consistent to the sensing principle). In the future, we believe the smart material-structure capable of sensing AC and DC magnetic fields will have more applications than conventional structures capable of sensing only DC or AC magnetic field. Thus, the smart material-structure will be an important design reference for future magnetic-field sensing technologies.
A Magnetic/Piezoelectric-Based Thermal Energy Harvester
(2013)
Chung, Tien-Kan
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Shukla, Ujjwal
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Tseng, Chia-Yuan
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Chen, Chin-Chung
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Wang, Chieh-Min
In this paper, we demonstrate a non-contact magnetic/piezoelectric-based thermal energy harvester utilizing an optimized thermal-convection mechanism to enhance the heat transfer in the energy harvesting/converting process in order to increase the power output. The harvester consists of a CuBe spring, Gadolinium soft magnet, NdFeB hard magnets, frame, and piezoelectric PZT cantilever beams. According to the configuration, the energy harvesting/converting process under a temperature-difference is cyclic. Thus, the piezoelectric beams continuously oscillate and subsequently produce voltage responses due to the piezoelectric effect. The maximum voltage response of the harvester under a temperature-difference of 25 degrees C is 16.6 mV with a cycling frequency of 0.58 Hz. In addition, we compare the testing result of the harvester utilizing the new thermal-convection mechanism reported in this paper and using previous thermal-convection mechanism reported elsewhere. According to the comparison, the results show the harvester utilizing the new thermal-convection mechanism has a higher cycling frequency resulting in a higher power output than the previous mechanism.
A Miniature Magnetic-Piezoelectric Thermal Energy Harvester
(2015-07-01)
Chen, Chin-Chung
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Chung, Tien-Kan
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Tseng, Chia-Yuan
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Hung, Chiao-Fang
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Yeh, Po-Chen
In this paper, we report a miniature thermal energy harvester with a novel magnetic-piezoelectric design. The harvester consists of a soft magnetic Gd cantilever beam, a piezoelectric lead zirconate titanate sheet, an NdFeB hard magnet, silicon clamps, and a silicon frame. In this design, the harvester is driven by a temperature difference between a cold side and room temperature ambient air, unlike other magnetic-piezoelectric thermal energy harvesters that are driven by a temperature difference between a cold side and a hot side or between two hot sides. Experimental results show that with a temperature difference of 20 degrees C (cold side: 6.7 degrees C, hot side: 26.7 degrees C), the harvester produces a maximum peak-to-peak voltage of 37 mV and a root mean square voltage of 1.98 mV. The estimated maximum instantaneous power density and average power density is 21.7 nW/cm(3) and 62.9 pW/cm(3), respectively. Moreover, the total volume of our harvester (length x width x height: 6 x 3.5 x 3 mm) is 217 times lower than that of previous experimental harvesters and 38 times smaller than that of previous theoretical-modeled harvesters. Therefore, our harvester is the smallest machined magnetic-piezoelectric thermal energy harvester designed to date. These features enable our harvester to be more easily implemented and integrated with micro wireless sensors and thereby increase more self-powered wireless-sensing applications.
A Miniature Mechanical-Piezoelectric-Configured Three-Axis Vibrational Energy Harvester
(2015-10-01)
Hung, Chiao-Fang
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Chung, Tien-Kan
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Yeh, Po-Chen
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Chen, Chin-Chung
;
Wang, Chieh-Min
In this paper, we demonstrate a novel robust miniature three-axis vibrational energy-harvester using a mechanical-piezoelectric configuration. Using the configuration, the harvester employs Newton\'s law of inertia and the piezoelectric effect to convert either the x-axis or y-axis in-plane and z-axis out-of-plane ambient vibrations into piezoelectric voltage-responses. Under the x-axis vibration (sine-wave, 75 Hz, 3.5 g), our modeled, finite-element analyzed/simulated, and experimental root mean square voltage-response with power-outputs of the harvester (stimulated in resonant with the optimum load) is 525.36 mV with 0.477 mu W, 516.51 mV with 0.461 mu W, and 548 mV with 0.519 mu W, respectively. Under the z-axis vibration (sine-wave, 95 Hz, 3.8 g), the modeled, finite-element analyzed/simulated, and experimental root mean square voltage-response with power-output of the harvester (stimulated in resonant with the optimum load) is 157.35 mV with 0.066 mu W, 170.25 mV with 0.0772 mu W, and 168 mV with 0.075 mu W, respectively. These show that not only both of our modeling and finite-element analysis/simulation can successfully predict the experimental results, but also our harvester is capable of harnessing three-axial ambient vibrations. Moreover, through the piezoelectric lead-zirconate-titanate-connected-in-series approach, the voltage and power outputs are increased. According to these achievements, we believe that our harvester would be an important design reference in industry for future development of microfabrication-based (MEMS-based) three-axial piezoelectric energy harvesters and accelerometers.
A NOVEL ELECTROMAGNETIC TARGETING SYSTEM USING ROTATING MAGNETIC-FLUX CONCENTRATION METHOD FOR NAVIGATING ENDOBRONCHOSCOPY
(2018-01-01)
Chen, Chin-Chung
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Lin, Ching-Kai
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Cheng, Yun-Chien
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Chang, Chen-Wei
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Tsai, Sung-Lin
In this paper, we proposed a novel electromagnetic targeting system using rotating magnetic-flux concentration method for navigating endo-bronchoscope. This system consists of a magnetic-flux emitting coil, a magnetic-flux receiving electromagnets-array, a 2D model of bronchial tree, the magnetic-flux concentrator embedded on brush-guiding tube which was connected to the guide sheath. When the concentrator in the 2D bronchial tree passes through the air gap between the emitting coil and the receiving electromagnets array, the concentrator concentrates the magnetic flux between the coil and the array. The concentrated magnetic flux is subsequently received by the receiving electromagnets-array and thus stable voltage output is produced. Furthermore, when the concentrator is rotated, the concentration of the magnetic flux is periodically changed and thereby the voltage output is periodically changed. By analyzing the voltage changes, the location of the concentrator (as well as guide tube and sheath) is targeted. According to the experimental results, the system successfully targets the location of the guide sheath in the 2D model of bronchial tree.
A NOVEL MECHANICAL-MECHANISM ENHANCED THERMOMAGNETIC TWEEZER DEMONSTRATING GRIPPING OF FERROMAGNETIC AND NON-FERROMAGNETIC OBJECTS
(2016)
Wang, Hsin-Min
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Chung, Tien-Kan
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Chen, Chin-Chung
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Cheng, Chih-Cheng
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Lin, Chu-Yi
In this article, we demonstrate a mechanical-mechanism enhanced thermomagnetic tweezer. The tweezer which utilizes a thermal-magnetic-mechanical converting consists of two cross jointed Al arms, two Gd sheets, two NdFeB hard magnets, two thermoelectric generators (TEGs), and a ball bearing set. When comparing conventional thermomagnetic grippers, our thermomagnetic tweezer can grip either ferromagnetic or non-ferromagnetic objects and avoid producing temperature-influence to the gripped objects. Experimental results show that we can control TEGs to generate a temperature difference to operate the tweezer to grip small ferromagnetic objects (such as NdFeB hard magnet) and other non-ferromagnetic objects (such as PMMA bulk). The maximum gripping force produced by the tweezer operated by applying the DC current of 1.3 A with the voltage of 0.85 V is 0.59 newton. The corresponding gripping and releasing duration is 7.9 seconds and 8.1 seconds, respectively. According to these results, our tweezer would produce more practical objects-gripping applications.
A Novel MEMS DC Magnetic Sensor Using Thermomagnetic-Piezoelectric Materials with a Coil-Less Reset Approach
(2018-01-01)
Chen, Chin-Chung
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Chen, I-Lun
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Duan, Hao
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Chung, Tien-Kan
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機械工程學系
We report a novel MEMS DC magnetic sensor using thermomagnetic-piezoelectric materials with a coil-less magnetization-reset approach. The magnetic sensor consists of a silicon MEMS diaphragm, a piezoelectric PZT thin film, and a thermomagnetic Gadolinium (Gd) sheet. Due to the Gd's thermomagnetic property, the sensor at low temperature (for instant, 9 degrees C.; below its Curie temperature which is in room temperature range) can sense ambient DC magnetic fields. Without using on-chip coils, the sensor can be easily reset by heating the sensor higher than its Curie temperature (for example, 45 degrees C. According to experimental results, the sensor successfully senses DC magnetic field from 2 to 100 Gauss and is 45 degrees C. When comparing to conventional NEMS, MEMS, and AMR magnetic sensors (i.e., using magnetic materials requiring on-chip magnetization-reset coils which occupy huge chip footprint), our sensor with the coil-less reset approach can significantly reduce the sensor footprint.
A Novel Miniature Thermomagnetic Energy Harvester
(2014)
Chen, Chin-Chung
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Chung, Tien-Kan
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Cheng, Chi-Cheng
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Tseng, Chia-Yuan
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機械工程學系
Nowadays, thermal-energy-harvesting is an important research topic for powering wireless sensors. Among numerous thermal-energy-harvesting approaches, some researchers demonstrated novel thermomagnetic-energy harvesters to convert a thermal-energy from an ambient temperature-difference to an electrical-output to power the sensors. However, the harvesters are too bulky to be integrated with the sensors embedded in tiny mechanical-structures for some structural-health-monitoring applications. Therefore, miniaturized harvesters are needed. Hence, we demonstrate a miniature thermomagnetic-energy harvester. The harvester consists of CuBe-beams, PZT-piezoelectric-sheet, Gd-soft-magnet, NdFeB-hard-magnet, and mechanical-frame. The piezoelectric-sheet and soft-magnet is bounded at fixed-end and free-end of the beams, respectively. The mechanical-frame assembles the beams and hard-magnet. The lengthxwidthxthickness of the harvester is 2.5cmx1.7cmx1.5cm. According to this, our harvester is 20-times smaller than the other harvesters. In the initial-state of the energy-harvesting, the beams\' free-end is near the cold-side. Thus, the soft-magnet is cooled lower than its curie temperature (Tc) and consequently changed from paramagnetic to ferromagnetic. Therefore, a magnetic-attractive force is produced between the soft-magnet and hard-magnet. Consequently, the beams/soft-magnet are down-pulled toward the hard-magnet fixed on the hot-side. The soft-magnet closing to the hot-side is heated higher than its Tc and subsequently changed to paramagnetic. Consequently, the magnetic-force is eliminated thus the beams are rebounded to the initial-state. Hence, when the harvester is under a temperature-difference, the beams\' pulling-down/back process is cyclic. Due to the piezoelectric effect, the piezoelectric-sheet fixed on the beams continuously produces voltage-response. Under the temperature-difference of 29 C, the voltage-response of the harvester is 30.4 mV with an oscillating-frequency of 0.098 Hz.
A NOVEL THERMOMAGNETIC ROTATIONAL-ACTUATOR
(2016)
Cheng, Chih-Cheng
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Chung, Tien-Kan
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Chen, Chin-Chung
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Wang, Hsin-Min
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機械工程學系
In this article, we demonstrate a novel thermomagnetic rotational-actuator. The actuator consists of thermomagnetic material Gadolinium sheets, thermoelectric generators, a rotary aluminum cantilever beam with NdFeB hard magnets fixed on the free-end of the beam, a stainless steel bearing, and a mechanical frame. As conventional magnetic rotational actuators are controlled by using electromagnetic-induction based magnetic-force interaction produced by electromagnets or coils, our actuator is controlled by using a heating-induced magnetic force interaction produced by the thermomagnetic generators. Experimental results show that our actuator is successfully rotated by a controlled sequence of temperature difference generated by the TEGs.
A Novel Thermomagnetic-Actuated Gripper With a Piezoelectric-Pyroelectric Sensing Readout of Gripping States and Forces
(2017-10-01)
Chen, Chin-Chung
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Chung, Tien-Kan
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Lin, Chu-Yi
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機械工程學系
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國際半導體學院
In this paper, we reported a thermomagnetic-actuated gripper with a piezoelectric-pyroelectric sensing readout of gripping states and forces. The gripper consists of two CuBe cantilever beams, a Gd sheet, NdFeB hard magnets, a thermoelectric generator (TEG), a piezoelectric-pyroelectric PZT sheet, and a polymer-polymethyl methacrylate base. When TEG cools the Gd sheet lower than its Curie temperature, the magnetic attraction between the Gd sheet and the NdFeB magnets is produced due to the thermomagnetic property of the Gd sheet. Subsequently, the magnetic attractive force deflects two beams until beams contact to each other. Thus, the gripper can grasp a small object. Furthermore, when the gripper is operated to grasp the object, the piezoelectric-pyroelectric PZT sheet of the gripper produces voltage response. Through analyzing the voltage response, the gripping state is detected and subsequently the gripping force is obtained. After gripping, a negative dc current is applied to TEG to heat the Gd sheet higher than Gd's Curie temperature. Due to this, the magnetic attractive force is reduced and eventually eliminated. Consequently, the beams are separated due to their spring-back force. Thus, the gripper releases the object. The experimental results show that the gripper can be sequentially operated to grasp and release the object. Furthermore, as the current applied to the TEG is increased, the gripping force is increased. The maximum gripping force of the gripper is 0.69 N when a dc current of 0.7 A is applied. Moreover, when comparing conventional magnetic-field-actuated magnetic grippers, our gripper can be individually operated by applied currents, detect the gripping state, and sense the gripping force.
A Rotational Actuator Using a Thermomagnetic-Induced Magnetic Force Interaction
(2018-01-01)
Cheng, Chih-Cheng
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Chung, Tien-Kan
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Chen, Chin-Chung
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Wang, Hsin-Min
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機械工程學系
In this paper, we demonstrate a rotational actuator using a thermomagnetic-induced magnetic force interaction. The actuator consists of a magnetic rotary beam, stainless-steel bearing, mechanical frame, thermomagnetic Gadolinium sheets, and thermoelectric generators (TEGs). Experimental results show that applying a sequence of currents to the TEGs successfully produces sequential magnetic forces. Consequently, these sequential magnetic forces rotate the beam for revolutions. When applying a sequence set of currents of -0.5 and 1.3 A, the maximum rotation speed and maximum stall torque of the actuator is 3.81 rpm and 136.2 mu Nm, respectively. Most importantly, the operating temperatures of other thermomagnetic (and electrothermal) actuators are usually high, but the operating temperature of our actuator is approximately room temperature (13 degrees C-27 degrees C). Therefore, our actuators have more practical applications. According to the above-mentioned features, we believe our actuator is an important alternative approach to developing future rotational actuators and motors.
A thermomagnetic-piezoelectric MEMS AC magnetic-field sensor demonstrating a novel room-temperature-range coil-less resetting/demagnetizing approach
(2019-10-01)
Chen, Chin-Chung
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Chen, I-Lun
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Duan, Hao
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Tseng, Chia-Yung
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Chung, Tien-Kan
We report a novel thermomagnetic-piezoelectric MEMS AC magnetic-field sensor. The magnetic sensor consists of a silicon MEMS diaphragm, a piezoelectric PZT thin film, and a thermomagnetic Gadolinium (Gd) film covered by a Pt anti-oxidation layer. Due to the thermomagnetic-Gd/piezoelectric-PZT layered structure, the sensor not only can sense AC magnetic field, but also can be reset/demagnetized automatically at temperature higher than Gd's Curie temperature which is in room-temperature range. Experimental results show that the sensor successfully senses AC magnetic field from 1 to 14 Gauss at 9 degrees C, and is automatically reset/demagnetized at 45 degrees C. While conventional MEMS and AMR magnetic sensors using magnetic materials require on-chip resetting/demagnetizing coils which need a huge footprint of the chip, our sensor utilizing the coil-less resetting/demagnetizing approach significantly reduces the sensor footprint. In the other hand, when comparing to conventional coil-less resetting/demagnetizing method (i.e., annealing magnetic material at hundreds degrees C), our coil-less resetting/demagnetizing approach is at room-temperature range (for instant, 45 degrees C). (C) 2019 Elsevier B.V. All rights reserved.
A Three-Axial Frequency-Tunable Piezoelectric Energy Harvester Using a Magnetic-Force Configuration
(2014-09-01)
Chung, Tien-Kan
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Wang, Chieh-Min
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Yeh, Po-Chen
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Liu, Tzu-Wei
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Tseng, Chia-Yuan
To date, researchers have utilized energy harvesters to power wireless sensor nodes as self-powered wireless sensors to create many innovative wireless sensors network applications such as medical monitoring, machining-condition monitoring, and structural-health monitoring. Regarding to energy harvesters, some researchers demonstrated wideband or frequency up-converted vibrational energy harvesters using magnetic force together with piezoelectric materials. However, these harvesters are not able to harness 3-D or three-axial mechanical energy through using one single mechanism or configuration. To address this problem, we report a novel magnetic-force-configured three-axial frequency-tunable piezoelectric energy harvester in this paper. Due to the magnetic-force configuration, the harvester converts ambient three-axial mechanical vibration/motion to piezoelectric voltage-response (i.e., three-axial energy harvesting). Simultaneously, the harvester also converts the ambient vibration/motion at a lower frequency to higher frequency without mechanical wear-out (i.e., noncontact frequency up-conversion). Through modifying the configuration, the oscillating frequency is tunable. By frequency tuning, the harvester\'s oscillating frequency and ambient vibration frequency are able to be matched to maximize the power output. Experimental results show the peak voltage, peak power, and frequency conversion of one single piezoelectric beam of the harvester under an in-plane and out-of-plane vibration is up to 800 mV, 640 nW, and from 7 to 56 Hz, and 27 mV, 729 pW, and from 1 to 294 Hz, respectively. These results confirm the harvester is capable of harnessing energy from 3-D and three-axial mechanical motion/vibration, addressing frequency-mismatching issue, avoiding mechanical wear-out problems, and producing a stable voltage output. Due to these, the energy-harvesting approach will enable more novel and practical wireless sensors network applications in the future.
DESIGN, FABRICATION, AND TESTING OF A THERMAL/MECHANICAL/MAGNETIC HYBRID ENERGY MICRO-HARVESTER
(2012)
Chung, Tien-Kan
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Tseng, Chia-Yuan
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Chen, Chin-Chung
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Wang, Chieh-Min
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機械工程學系
In this paper, we report a novel hybrid energy micro-harvester. The harvester utilizes ferromagnetic materials combined with piezoelectric cantilever beams to harvest the energy from a thermal, mechanical, and magnetic energy sources and subsequently convert the energy to an electrical output. In addition to energy-harvesting, the harvester utilizes a non-contact approach in its structure to avoid the wear problem which frequently occurs in conventional structural-contact approaches.
Electromagnetic/Magnetic-Coupled Targeting System for Screw-Hole Locating in Intramedullary Interlocking-Nail Surgery
(2014-12-01)
Wong, Tze-Hong
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Chung, Tien-Kan
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Liu, Tzu-Wei
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Chu, Hou-Jen
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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.
FINITE ELEMENT MODELING OF ELECTROMAGNETIC-COILS TARGETING SYSTEM FOR LOCATING DISTAL SCREW-HOLE IN INTRAMEDULLARY INTERLOCKING-NAIL SURGERY
(2018-01-01)
Cheng, Ya-Wen
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Chen, Po-Wen
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Wong, Tze-Hong
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Chen, Chin-Chung
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Hsu, Wensyang
In this paper, we report a finite element modeling of an electromagnetic-coils targeting system to locate a distal screw hole in intramedullary interlocking-nail surgery. The system consists of an internal coil, external coil, and control/measurement electronics. The internal coil is embedded in a distal screw-hole of the nail inserted into the bone. A current is applied to the internal coil to produce a directional magnetic flux penetrating the nail/bone. Thus, the external coil scans different regions of the nail/bone will receive different amount of magnetic flux, and thereby produces different voltage outputs due to the electromagnetic induction. By analyzing the voltage outputs, the distal screw-hole is targeted. However, to precisely apply this system to many different nails for people in different regions, modification and optimization of the system are needed. For rapid modification and optimization, we implement finite element method to model the targeting system. Because the modeling results are qualitatively consistent to experimental results, the modeling is successfully validated to be able to qualitatively predict experimental trends and thereby can be used for rapid system modification and optimization.
Passive Magnetic-Flux-Concentrator Based Electromagnetic Targeting System for Endobronchoscopy
(2019-12-01)
Chen, Chin-Chung
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Lin, Ching-Kai
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Chang, Chen-Wei
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Cheng, Yun-Chien
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Chen, Jia-En
In this paper, we demonstrate an innovative electromagnetic targeting system utilizing a passive magnetic-flux-concentrator for tracking endobronchoscope used in the diagnosis process of lung cancer tumors/lesions. The system consists of a magnetic-flux emitting coil, a magnetic-flux receiving electromagnets-array, and high permeability silicon-steel sheets rolled as a collar (as the passive magnetic-flux-concentrator) fixed in a guide sheath of an endobronchoscope. The emitting coil is used to produce AC magnetic-flux, which is consequently received by the receiving electromagnets-array. Due to the electromagnetic-induction, a voltage is induced in the receiving electromagnets-array. When the endobronchoscope's guide sheath (with the silicon-steel collar) travels between the emitting coil and the receiving electromagnets-arrays, the magnetic flux is concentrated by the silicon-steel collar and thereby the induced voltage is changed. Through analyzing the voltage-pattern change, the location of the silicon-steel collar with the guide sheath is targeted. For testing, a bronchial-tree model for training medical doctors and operators is used to test our system. According to experimental results, the system is successfully verified to be able to target the endobronchoscope in the bronchial-tree model. The targeting errors on the x-, y- and z-axes are 9 mm, 10 mm, and 5 mm, respectively.
Self-Magnetization-Switchable Micro-Magnetic Track Based Magnetic-Bead Manipulation
(2018-01-01)
Chung, Tien-Kan
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Fang, Lin-Huei
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Liu, Tzu-Wei
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Chu, Hou-Jen
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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.
THERMOMAGNETIC MICRO-TRACKS-GUIDED MAGNETIC BEAD MANIPULATION: A DEMONSTRATION OF MOVING BEAD ACROSS DIFFERENT TRACKS ENABLED BY NOVEL EMBEDDED ON-CHIP MICRO HEATING WIRES
(2019-01-01)
Fang, Lin-Huei
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Duan, Hao
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Chen, Chin-Chung
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Cheng, Chin-Cheng
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Chung, Tien-Kan
In this paper, we show a demonstration of moving bead across different tracks enabled by novel embedded on-chip micro heating wires for thermomagnetic micro-tracks-guided magnetic bead manipulation. The demonstration includes a magnetic-bead-manipulation chip (which consists of thermomagnetic NiCu micro-disk tracks deposited on top of on-chip platinum micro heating wires fabricated on top of a silicon substrate), a magnetic bead, a thermoelectric generator (TEG), a pulse-generation circuit, and four external electromagnets. Because curie temperature of the track is approximate in room-temperature range, when we apply a pulse current to the heating wires to individually heat the track higher than room temperature, the magnetic property of the track is switched to paramagnetic. Oppositely, when we apply a current to TEG to cool the track lower than room temperature, the track is switched to ferromagnetic. By sequentially/selectively heating or cooling the tracks to switch the tracks to paramagnetic or ferromagnetic, together with applying directional magnetic field, we can achieve moving bead across different NiCu micro-disk tracks. This is an important and significant progress for conventional thermomagnetic micro-tracks-guided magnetic bead manipulation which cannot demonstrate moving bead across different tracks. Therefore, our approach provides a new and complete thermomagnetic micro-tracks-guided magnetic bead manipulation for lab-on-chip micro systems and biomedical MEMS/NEMS.