| NSF Org: |
ECCS Div Of Electrical, Commun & Cyber Sys |
| Recipient: |
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| Initial Amendment Date: | April 8, 2011 |
| Latest Amendment Date: | April 16, 2013 |
| Award Number: | 1102280 |
| Award Instrument: | Continuing Grant |
| Program Manager: |
Mona Zaghloul
ECCS Div Of Electrical, Commun & Cyber Sys ENG Directorate For Engineering |
| Start Date: | May 1, 2011 |
| End Date: | April 30, 2016 (Estimated) |
| Total Intended Award Amount: | $359,999.00 |
| Total Awarded Amount to Date: | $359,999.00 |
| Funds Obligated to Date: |
FY 2012 = $119,475.00 FY 2013 = $122,466.00 |
| History of Investigator: |
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| Recipient Sponsored Research Office: |
4000 CENTRAL FLORIDA BLVD ORLANDO FL US 32816-8005 (407)823-0387 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
4000 CENTRAL FLORIDA BLVD ORLANDO FL US 32816-8005 |
| Primary Place of Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | CCSS-Comms Circuits & Sens Sys |
| Primary Program Source: |
01001213DB NSF RESEARCH & RELATED ACTIVIT 01001314DB NSF RESEARCH & RELATED ACTIVIT |
| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.041 |
ABSTRACT
Droplet Thermotaxis: A New Platform Technology for Droplet-based Microfluidic Systems
Abstract
The objective of this program is to develop a new platform technology for droplet-based microfluidic systems and demonstrate chemical unit operations using the developed platform for applications in chemistry and biology based on the study of the fundamental science of thermotaxis actuation.
The intellectual merit is found at the cross-section of electrical engineering, mechanical engineering and chemistry, laying the solid foundation and design guidelines for various microfluidic devices and systems that can take advantage of the newly discovered droplet actuation mechanisms. The proposed work will provide fundamental information for understanding the dual behavior of droplets, underlying science of unique transport mechanisms at the interfacial boundaries (liquid-liquid, liquid-air, liquid-solid), practical tool kits for droplet-based chemical experiments, methodology for optical diagnostics of miniaturized devices and systems, and novel experimental protocols for controlled chemical reactions.
The broader impacts are summarized as (a) wide applicability of our technology for handling liquid samples in a self-confined configuration and for the effective thermal management of droplets relevant to many disciplines (b) dissemination of cultivated knowledge to research communities across electrical engineering, mechanical engineering, chemistry and biology and (c) long-lasting educational outcomes from thoughtfully designed multidisciplinary mentorship and outreach activities involving undergraduate, graduate and K-12 students.
This program is built upon a new and transformative discovery ? bidirectional droplet actuation based on the surface film deformation, unlike the traditional approach. This program will help understand the defining science and working principles so the newly proposed actuation mechanism may be favorably used for miniaturized devices and systems.
PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH
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PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
The objective of this project is to develop a new platform technology for manipulating droplets that can be used one day for rapid chemical analysis systems. On contrary to a common belief that a surface of a liquid in a container is flat, this work is based on the research team’s counter-intuitive observation - the liquid surface could be curved upon heating due to a change of surface tension.
A floating spherical water droplet with a thin air gap could be formed on an oil film and used as a carrier that contains chemicals. A stable configuration of the droplet at the air-oil interface depends on the height from which the droplet is released and the size of the droplet. When a small water droplet is released from a certain height from the inert oil surface, it can sustain the impact, preserve its spherical shape, and levitate on the oil film surface. When the oil is heated locally using a microheater, a temperature difference between hot and cold sections creates deformation of oil surface with a downhill slope towards the hot spot due to the surface tension effect. Then the droplet moves down the surface slope because of gravity. The droplet acts like a hovercraft that glides over the oil surface with an air cushion.
Force and energy analysis on this interesting configuration revealed that physics behind this counterintuitive observation – bending of a horizontal liquid surface. The research team discovered underlying science of unique transport mechanisms at the interfacial boundaries (liquid-liquid, liquid-air, liquid-solid), and developed practical tool kits for droplet-based chemical experiments, found methodology for optical diagnostics of miniaturized devices and systems, and provided novel experimental protocols for controlled chemical reactions.
The methodology that is developed throughout this project can be used for effective thermal management of droplets, which is critical to understanding heating or cooling mechanisms of electronic devices and thermal systems as well as chemical and biological systems. The findings in this fundamental study can be beneficial to many applications that need to deal with a small amount of chemical and biological liquid samples. The project successfully demonstrated the applicability of the theoretical framework to the practical aspects of chemical and biological sensing.
Last Modified: 07/08/2016
Modified by: Hyoung Jin Cho
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A droplet-based chemical experiment which shows transporting, trapping, coalescing, and mixing. Microheaters on a silicon wafer are switched on and off to create local hot spots. Droplets move towards hot spots due to the downhill slope generated by the deformed oil film.Alireza Karbalaei, Ashkan Davanlou, Alireza Karbalaei, Ranganathan Kumar, Hyoung Jin ChoRoyalty-free (restricted use - cannot be shared)Please report errors in award information by writing to: awardsearch@nsf.gov.
