Transistor off-Valve Based Feedback, Metering and Logic Operations in Capillary Microfluidics

Meffan, Robert Claude; Menges, Julian; Dolamore, Fabian; Fee, Conan J.; Dobson, Renwick C. J.; Nock, Volker

doi:10.1109/mems51782.2021.9375175

“…To fill this gap, we demonstrated autonomous capillary-action fluidic valving, with no need for external instrumentation, and a variety of fundamental valving operations, including use to provide feedback, metering and logic operations. 26 As eluded to in our previous work, the off-valves hold the potential for more transistor-like switching and resistance tuning. This stems from the construction and operational principle of the off-valve, which are shown in Fig.…”

Section: Introductionmentioning

confidence: 88%

Capillaric - Field Effect Transistors

Meffan

¹

,

Menges

²

,

Dolamore

³

et al. 2021

Preprint

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Controling fluid flow in capillaric circuits is a key requirement to increase their uptake for assay applications. Capillary action off-valves provide such functionality by pushing an occluding bubble into the channel using a difference in capillary pressure. Previously, we utilised the binary switching mode of this structure to develop a powerful set of fundamental fluidic valving operations. In this work we provide evidence that these structures are in fact functionally complementary to electronic Junction Field Effect Transistors and thus warrant the use of the new term of capillaric- Field Effect Transistor to describe these types of valves. To support this conclusion, we present a theoretical description, experimental characterisation, and practical application of analog flow resistance control. In addition, we demonstrate that the valves can also be re-opened. These are two key capabilities previously missing for a full analogy to electronic transistors. We show modulation of the flow resistance from fully open to pinch-off, determine the flow rate – trigger channel volume relationship and demonstrate that the latter can be modelled using Shockley’s equation for electronic transistors. Finally, we provide a first example of how the valves can be opened and closed repeatedly.

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“…Devices were fabricated from cross-linked polymethylmethacrylate (PMMA; 4.5 mm general purpose acrylic; PSP Plastics, Christchurch, New Zealand) as previously described. 22,26 Channel milling was performed using a Mini-Mill/GX micro milling machine running a NSK-3000 Spindle (Minitech Machinery Corporation, Norcross, GA, USA), with a minimum adressable step size of 1 µm. Machining tools were purchased from Performance Micro Tool (Janesville, WI, Each sample was fabricated by an initial face cut (3.175 mm cutter) to level out the surface, followed by milling of each channel.…”

Section: Fabricationmentioning

confidence: 99%

Capillaric - Field Effect Transistors

Meffan

¹

,

Menges

²

,

Dolamore

³

et al. 2021

Preprint

Self Cite

0

View full text Add to dashboard Cite

Controling fluid flow in capillaric circuits is a key requirement to increase their uptake for assay applications. Capillary action off-valves provide such functionality by pushing an occluding bubble into the channel using a difference in capillary pressure. Previously, we utilised the binary switching mode of this structure to develop a powerful set of fundamental fluidic valving operations. In this work we provide evidence that these structures are in fact functionally complementary to electronic Junction Field Effect Transistors and thus warrant the use of the new term of capillaric-Field Effect Transistor to describe these types of valves. To support this conclusion, we present a theoretical description, experimental characterisation, and practical application of analog flow resistance control. In addition, we demonstrate that the valves can also be re-opened. These are two key capabilities previously missing for a full analogy to electronic transistors. We show modulation of the flow resistance from fully open to pinch-off, determine the flow ratetrigger channel volume relationship and demonstrate that the latter can be modeled using Shockley's equation for electronic transistors. Finally, we provide a first example of how the valves can be opened and closed repeatedly.

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“…S1) according to methods described in detail in our previous work. 22,26 As per its design, this chip systematically varied the trigger channel volume of a number of cFETs to place the occluding bubbling in a range of states. These states are essentially stable snapshots of the meniscus at discrete time points throughout the complete closing of the cFET.…”

Section: Transient Dynamics Of the Cfetmentioning

confidence: 99%

“…The chip utilised to experimentally demonstrate this was a modified version of a multiple-input NAND device reported previously (CAD files provided in the ESI). 26 This device consists of multiple trigger channels which lead into a single void volume. In its ordinary operation, the valve operates like a computational NAND function, completely closing only when all the trigger channels have been actuated.…”

Section: Reversible Operation Of the Cfetmentioning

confidence: 99%

“…Devices were fabricated from cross-linked polymethylmethacrylate (PMMA; 4.5 mm general purpose acrylic; PSP Plastics, Christchurch, New Zealand) as previously described. 22,26 Channel milling was performed using a Mini-Mill/GX Each sample was fabricated by an initial face cut (3.175 mm cutter) to level out the surface, followed by milling of each channel. Milling shallower channels was carried out first to avoid burring on the edges, and all channel steps were repeated at bottom height at the end of milling to remove burrs.…”

Section: Fabricationmentioning

confidence: 99%

See 1 more Smart Citation

Capillaric - Field Effect Transistors

Meffan

¹

,

Menges

²

,

Dolamore

³

et al. 2021

Preprint

Self Cite

0

View full text Add to dashboard Cite

Controling fluid flow in capillaric circuits is a key requirement to increase their uptake for assay applications. Capillary action off-valves provide such functionality by pushing an occluding bubble into the channel using a difference in capillary pressure. Previously, we utilised the binary switching mode of this structure to develop a powerful set of fundamental fluidic valving operations. In this work we provide evidence that these structures are in fact functionally complementary to electronic Junction Field Effect Transistors and thus warrant the use of the new term of capillaric- Field Effect Transistor to describe these types of valves. To support this conclusion, we present a theoretical description, experimental characterisation, and practical application of analog flow resistance control. In addition, we demonstrate that the valves can also be re-opened. These are two key capabilities previously missing for a full analogy to electronic transistors. We show modulation of the flow resistance from fully open to pinch-off, determine the flow rate – trigger channel volume relationship and demonstrate that the latter can be modelled using Shockley’s equation for electronic transistors. Finally, we provide a first example of how the valves can be opened and closed repeatedly.

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Transistor off-Valve Based Feedback, Metering and Logic Operations in Capillary Microfluidics

Cited by 7 publications

References 7 publications

Capillaric - Field Effect Transistors

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