Abstract
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 article presents the characteristics of EWOD device with aluminum oxide (Al 2O 3, ε r ≈ 10) deposited by atomic layer deposition (ALD), for the first time 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 1 mm × 1 mm squares with 50 μm space, the dielectric layer of 1,270 Å thick ALD Al 2O 3, the reference electrode of 20 μm wide line electrode, and the hydrophobic surface treatment by Teflon-AF coating, respectively. We observed the movement of a 2 μl water droplet in an air environment, applying a voltage between one of the control electrodes and the reference electrode in contact with the droplet. The droplet velocity exponentially depending on the applied voltage below 15 V was obtained. The measured threshold voltage to move the droplet was as low as 3 V 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 Al 2O 3 as the dielectric.
| Original language | English |
|---|---|
| Pages (from-to) | 269-273 |
| Number of pages | 5 |
| Journal | Microfluidics and Nanofluidics |
| Volume | 8 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - 2010 Feb 1 |
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Keywords
- Aluminum oxide (Al O )
- Atomic layer deposition (ALD)
- Digital microfluidics
- Electrowetting on dielectric (EWOD)
- Single-plate configuration
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials
- Materials Chemistry
Cite this
Driving characteristics of the electrowetting-on-dielectric device using atomic-layer-deposited aluminum oxide as the dielectric. / Chang, Jong Hyeon; Choi, Dae Young; Han, Seungoh; Pak, James Jungho.
In: Microfluidics and Nanofluidics, Vol. 8, No. 2, 01.02.2010, p. 269-273.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Driving characteristics of the electrowetting-on-dielectric device using atomic-layer-deposited aluminum oxide as the dielectric
AU - Chang, Jong Hyeon
AU - Choi, Dae Young
AU - Han, Seungoh
AU - Pak, James Jungho
PY - 2010/2/1
Y1 - 2010/2/1
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 article presents the characteristics of EWOD device with aluminum oxide (Al 2O 3, ε r ≈ 10) deposited by atomic layer deposition (ALD), for the first time 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 1 mm × 1 mm squares with 50 μm space, the dielectric layer of 1,270 Å thick ALD Al 2O 3, the reference electrode of 20 μm wide line electrode, and the hydrophobic surface treatment by Teflon-AF coating, respectively. We observed the movement of a 2 μl water droplet in an air environment, applying a voltage between one of the control electrodes and the reference electrode in contact with the droplet. The droplet velocity exponentially depending on the applied voltage below 15 V was obtained. The measured threshold voltage to move the droplet was as low as 3 V 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 Al 2O 3 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 article presents the characteristics of EWOD device with aluminum oxide (Al 2O 3, ε r ≈ 10) deposited by atomic layer deposition (ALD), for the first time 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 1 mm × 1 mm squares with 50 μm space, the dielectric layer of 1,270 Å thick ALD Al 2O 3, the reference electrode of 20 μm wide line electrode, and the hydrophobic surface treatment by Teflon-AF coating, respectively. We observed the movement of a 2 μl water droplet in an air environment, applying a voltage between one of the control electrodes and the reference electrode in contact with the droplet. The droplet velocity exponentially depending on the applied voltage below 15 V was obtained. The measured threshold voltage to move the droplet was as low as 3 V 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 Al 2O 3 as the dielectric.
KW - Aluminum oxide (Al O )
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=77649238688&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77649238688&partnerID=8YFLogxK
U2 - 10.1007/s10404-009-0511-9
DO - 10.1007/s10404-009-0511-9
M3 - Article
AN - SCOPUS:77649238688
VL - 8
SP - 269
EP - 273
JO - Microfluidics and Nanofluidics
JF - Microfluidics and Nanofluidics
SN - 1613-4982
IS - 2
ER -