Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting
We present experimental studies of alternating current (AC) electrowetting dominantly influenced by several unique characteristics of an ion gel dielectric in its capacitance. At a high-frequency region above 1 kHz, the droplet undergoes the contact angle modification. Due to its high-capacitance ch...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-03-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/12/3/320 |
| _version_ | 1797540871788298240 |
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| author | Taewoo Lee Sung-Yong Park |
| author_facet | Taewoo Lee Sung-Yong Park |
| author_sort | Taewoo Lee |
| collection | DOAJ |
| description | We present experimental studies of alternating current (AC) electrowetting dominantly influenced by several unique characteristics of an ion gel dielectric in its capacitance. At a high-frequency region above 1 kHz, the droplet undergoes the contact angle modification. Due to its high-capacitance characteristic, the ion gel allows the contact angle change as large as Δ<i>θ</i> = 26.4°, more than 2-fold improvement, compared to conventional dielectrics when <i>f</i> = 1 kHz. At the frequency range from 1 to 15 kHz, the capacitive response of the gel layer dominates and results in a nominal variation in the angle change as <i>θ</i> ≈ 90.9°. Above 15 kHz, such a capacitive response of the gel layer sharply decreases and leads to the drastic increase in the contact angle. At a low-frequency region below a few hundred Hz, the droplet’s oscillation relying on the AC frequency applied was mainly observed and oscillation performance was maximized at corresponding resonance frequencies. With the high-capacitance feature, the ion gel significantly enlarges the oscillation performance by 73.8% at the 1st resonance mode. The study herein on the ion gel dielectric will help for various AC electrowetting applications with the benefits of mixing enhancement, large contact angle modification, and frequency-independent control. |
| first_indexed | 2024-03-10T13:07:12Z |
| format | Article |
| id | doaj.art-d50e5905154d4051afa60abe23f15173 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-10T13:07:12Z |
| publishDate | 2021-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-d50e5905154d4051afa60abe23f151732023-11-21T11:01:42ZengMDPI AGMicromachines2072-666X2021-03-0112332010.3390/mi12030320Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC ElectrowettingTaewoo Lee0Sung-Yong Park1Department of Mechanical Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore 117576, SingaporeDepartment of Mechanical Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182, USAWe present experimental studies of alternating current (AC) electrowetting dominantly influenced by several unique characteristics of an ion gel dielectric in its capacitance. At a high-frequency region above 1 kHz, the droplet undergoes the contact angle modification. Due to its high-capacitance characteristic, the ion gel allows the contact angle change as large as Δ<i>θ</i> = 26.4°, more than 2-fold improvement, compared to conventional dielectrics when <i>f</i> = 1 kHz. At the frequency range from 1 to 15 kHz, the capacitive response of the gel layer dominates and results in a nominal variation in the angle change as <i>θ</i> ≈ 90.9°. Above 15 kHz, such a capacitive response of the gel layer sharply decreases and leads to the drastic increase in the contact angle. At a low-frequency region below a few hundred Hz, the droplet’s oscillation relying on the AC frequency applied was mainly observed and oscillation performance was maximized at corresponding resonance frequencies. With the high-capacitance feature, the ion gel significantly enlarges the oscillation performance by 73.8% at the 1st resonance mode. The study herein on the ion gel dielectric will help for various AC electrowetting applications with the benefits of mixing enhancement, large contact angle modification, and frequency-independent control.https://www.mdpi.com/2072-666X/12/3/320AC electrowettingion gelcontact angle modulationdroplet oscillationhigh capacitance |
| spellingShingle | Taewoo Lee Sung-Yong Park Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting Micromachines AC electrowetting ion gel contact angle modulation droplet oscillation high capacitance |
| title | Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting |
| title_full | Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting |
| title_fullStr | Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting |
| title_full_unstemmed | Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting |
| title_short | Capacitance Effects of a Hydrophobic-Coated Ion Gel Dielectric on AC Electrowetting |
| title_sort | capacitance effects of a hydrophobic coated ion gel dielectric on ac electrowetting |
| topic | AC electrowetting ion gel contact angle modulation droplet oscillation high capacitance |
| url | https://www.mdpi.com/2072-666X/12/3/320 |
| work_keys_str_mv | AT taewoolee capacitanceeffectsofahydrophobiccoatediongeldielectriconacelectrowetting AT sungyongpark capacitanceeffectsofahydrophobiccoatediongeldielectriconacelectrowetting |