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W.K. Schomburg

RWTH Aachen, KEmikro

Ultrasonic Fabrication of Disposable Medical

Analysis and Dosing Systems

F

www.KEmikro.RWTH-Aachen.de

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Outline

Ultrasonic hot embossing

Welding in of fluidic and electric connections

Ultrasonic welding

Conclusions

Flow sensors

Detection of a Taylor flow

Micro fluidic chips

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Ultrasonic hot embossing

Downstroke

Sonotrode

Polymer foils

Tool

Time [s]0 1 2.50.5 1.5 2

Travel

Ultrasonic hot embossing

Force

Time [s]0

Position

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1 2.50.5 1.5 2

Force BuildupDownstroke

F

Ultrasonic hot embossing

Force

Time [s]0

Position

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1 2.50.5 1.5 2

MeltingForce BuildupDownstroke

Ultrasonic

vibrationsF

F

Ultrasonic hot embossing

Force

Time [s]0

Position

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1 2.50.5 1.5 2

MeltingForce BuildupDownstroke

Ultrasonic

vibrationsF

F

Solidification

F

Ultrasonic hot embossing

Demolding

Force

Time [s]0

Position

Solidification

F

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1 2.50.5 1.5 2

MeltingForce BuildupDownstroke

Ultrasonic

vibrationsF

F

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Ultrasonic hot embossing

Demolding

Force

Time [s]1 2.50.5 1.5 20

Position500µm

5mm

MeltingForce BuildupDownstroke

Ultrasonic

vibrationsF

F

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Ultrasonic hot embossing

of colored polymer layers

Cut through

micro structureWith

ultrasound

Without

ultrasound

The polymer is stirred by the ultrasound.

Sonotrode

Polymer

foils

Tool

Heating

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Ultrasonic welding with energy director

Force buildup

F

Downstroke Melting

Ultrasonic

vibrations

F F

Solidification Releasing

Energy

director Micro

groove

Polymer

foil

500 µm

Energy director Micro channel

500 µm

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Ultrasonic welding with metal wire

Down stroke

Notch

Micro

groove

Polymer

foil

Melting

Ultraschall

F F

SolidificationForce buildup

F

Wire

* L. Hoehr, J. Sackmann, W.K. Schomburg, ” Ultraschallschweißen mit Einlegeteilen”, Kunststoffe 3 (2017)

Wire Micro channel

500 µm

Micro channel from PC

*

500 µm

Wire Micro channel

Micro channel from FEP

*

Releasing

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Ultrasonic hot embossing and welding

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Roll-to-roll production

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Welding in of fluidic and electrical

connections

500 µm

Hose

75 µm

Copper wire

Polymer foils

Polymer

foilEnergy

directorWire

Polymer

foilEnergy

director Hose

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Fluidic connections

Hoses Luer connectors

TubesScrewed connections

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Hot Wire Anemometer

72

74

76

78

80

0 20 40 60v' [ml/h]

U [

mV

]

Volume flow [mL/h]

Um

[mV

]

Heater wire

50 µm thick

Um

I0

Inlet Outlet

V

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Measurement of flow time

∆t

Water

Ethanol

Oil 2Oil 1

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Flow parallel wire (FPW)

2 A

Um

50 mA

FPW

HeaterV

Time [s]

Water

Oil 2Oil 1

tm0.3

0.2

0.1

0

Um

[V]

t m[s

]

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Taylor flow

Slug

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Taylor flow detection

Soldered

connections

Channel with

liquid-liquid

Taylor flow

PVDF channel

0.5 × 0.5 mm²

Parallel Gold wires,

50 µm in thickness

PVDF

Block

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Slug Detection

0.6

0

-0.60 1 2 3 54

Curr

ent

[mA

]

Time [s]

Gold wires

Conductive phase

A

~

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Cell chip

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Cell culture chip

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Cells growing in a chip

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Calcification risk

Healthy mouse

Calcified mouse

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Analysis chip for calcification risk

Micro mixer

Cuvette to observe

precipitation time

Bubble catchersInlet for

blood serum Inlet for calcium and phosphate

4,30

4,35

4,40

4,45

4,50

0 100

Tu

rbid

ity [a

.u.]

Time [min]

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Possible Polymers

In principle all thermoplastic

polymers can be used.

We have tested:

PP

PEEK

PVDF

PVC

PC

PA

PS

PE

MABS

PMMA

LDPE

SAN

PLA PET FEP

PTFE

TPU

PPSU

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Conclusions

affordable

Ultrasonic processing

of analysis and dosing systems is

even for small-scale production:

A welding machine is commercially available for a few 10.000 €.

quick

In one day a new design can be realized.

In a few minutes a tool or the polymer can be exchanged.

In a few seconds a new product is fabricated.

flexible

A lot of micro systems can be fabricated from a variety of polymers.