TY - GEN
T1 - Low voltage electrowetting on atomic-layer-deposited aluminum oxide
AU - Chang, Jong Hyeon
AU - Choi, Dae Young
AU - You, Xueqiu
AU - Pak, James Jungho
AU - Han, Seungoh
PY - 2010
Y1 - 2010
N2 - Electrowetting on dielectric (EWOD) is useful in manipulating droplets for digital (droplet-based) microfluidics, but its high driving voltage over several tens of volts has been a barrier to overcome. This paper presents the characteristics of EWOD device with aluminum oxide (Al2O3, εr≈10), deposited by atomic layer deposition (ALD), as the high-k dielectric for lowering the EWOD driving voltage substantially. The EWOD device of the single-plate configuration was fabricated by several steps for the control electrode array of 1mmx1mm squares with 50μm space, the dielectric layer of 127nm thick ALD Al2O3, the reference electrode of 20μm wide line electrode, and the hydrophobic surface treatment by Teflon-AF coating, respectively. We observed the movement of a 2μl water droplet in an air environment, applying a voltage between one of the control electrodes and the reference electrode in contact with the droplet. Exponentially increasing droplet velocity with the applied voltage was obtained below 15V. The measured threshold voltage to move the droplet was as low as 3V which is the lowest voltage reported so far in the EWOD researches. This result opens a possibility of manipulating droplets, without any surfactant or oil treatment, at only a few volts by EWOD using ALD Al2O3 as the dielectric.
AB - Electrowetting on dielectric (EWOD) is useful in manipulating droplets for digital (droplet-based) microfluidics, but its high driving voltage over several tens of volts has been a barrier to overcome. This paper presents the characteristics of EWOD device with aluminum oxide (Al2O3, εr≈10), deposited by atomic layer deposition (ALD), as the high-k dielectric for lowering the EWOD driving voltage substantially. The EWOD device of the single-plate configuration was fabricated by several steps for the control electrode array of 1mmx1mm squares with 50μm space, the dielectric layer of 127nm thick ALD Al2O3, the reference electrode of 20μm wide line electrode, and the hydrophobic surface treatment by Teflon-AF coating, respectively. We observed the movement of a 2μl water droplet in an air environment, applying a voltage between one of the control electrodes and the reference electrode in contact with the droplet. Exponentially increasing droplet velocity with the applied voltage was obtained below 15V. The measured threshold voltage to move the droplet was as low as 3V which is the lowest voltage reported so far in the EWOD researches. This result opens a possibility of manipulating droplets, without any surfactant or oil treatment, at only a few volts by EWOD using ALD Al2O3 as the dielectric.
KW - Aluminum oxide (AlO)
KW - Atomic layer deposition (ALD)
KW - Digital microfluidics
KW - Electrowetting on dielectric (EWOD)
KW - Single-plate configuration
UR - http://www.scopus.com/inward/record.url?scp=78649236990&partnerID=8YFLogxK
U2 - 10.1109/NEMS.2010.5592477
DO - 10.1109/NEMS.2010.5592477
M3 - Conference contribution
AN - SCOPUS:78649236990
SN - 9781424465439
T3 - 2010 IEEE 5th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
SP - 612
EP - 615
BT - 2010 IEEE 5th International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
T2 - 5th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2010
Y2 - 20 January 2010 through 23 January 2010
ER -