Abgeschlossene Dissertationen
Microfluidic Chemical Integrated Circuits Based on Stimuli-Responsive Hydrogels for On-Chip Flow Control
Art der Abschlussarbeit
Dissertation
Autoren
- Frank, Philipp
Betreuer
- Prof. Dr.-Ing. Andreas Richter
Abstract
Microfluidics exhibits great capability in various research fields such as biology, chemistry or medicine.
The lab-on-a-chip technology brings tremendous advantages over the conventional methods as it
increases reaction kinetics, reduces reagent consumption and provides high throughput and parallelization
capability. The aspect of parallelization on a large scale requires a powerful control
paradigm where a large number of devices need to be manipulated by a small number of inputs.
Even though, microfluidics has produced a variety of different platform technologies utilizing the
most different physical effects the majority of technologies lack the ability to act on direct feedback
from the process liquid. This results in a sophisticated external control unit off-chip which directly
hinders high degrees of parallelization respectively integration.
This work presents a microfluidic platform concept, which utilizes the volume phase transition of
stimuli-responsive hydrogels on-chip to actively switch between fluid streams in a discrete operating
manner. The volume phase transition combines the sensing and acting functionality in one component.
Smart hydrogels are utilized in a transistor-like device which is capable to autonomously
make switching decision exclusively depending on the chemical content of a fluid. The content
comprising molecules and ions that exist simultaneously in a solution is viewed as carrier of chemical
information. Thus, the chemo-fluidic transistor couples the molecular content of the liquid with
the fluidic behavior of the system.
The combination of the chemo-fluidic transistor and the analogy between electronics and microfluidic
allowed the development of discrete basic circuits such as the logic gates AND, OR, NOT,
and their negated counterparts rendering a complete computation. By consequently following the
electronic paradigm more sophisticated modules are demonstrated such as an RS flip-flop or a
chemo-fluidic oscillator circuit. The chemo-fluidic oscillator exhibits an autonomous oscillation in
flow rate and concentration. The system architecture and circuitry allows a decoupling of the excitation
stimulus and the emission concentration enabling future biological and medical application.
This work discusses a novel concept for the implementation of microfluidic integrated circuits. Main
aspects are examined such as technological requirements, the theoretical background, the signal
variability and biological application of the system.
The lab-on-a-chip technology brings tremendous advantages over the conventional methods as it
increases reaction kinetics, reduces reagent consumption and provides high throughput and parallelization
capability. The aspect of parallelization on a large scale requires a powerful control
paradigm where a large number of devices need to be manipulated by a small number of inputs.
Even though, microfluidics has produced a variety of different platform technologies utilizing the
most different physical effects the majority of technologies lack the ability to act on direct feedback
from the process liquid. This results in a sophisticated external control unit off-chip which directly
hinders high degrees of parallelization respectively integration.
This work presents a microfluidic platform concept, which utilizes the volume phase transition of
stimuli-responsive hydrogels on-chip to actively switch between fluid streams in a discrete operating
manner. The volume phase transition combines the sensing and acting functionality in one component.
Smart hydrogels are utilized in a transistor-like device which is capable to autonomously
make switching decision exclusively depending on the chemical content of a fluid. The content
comprising molecules and ions that exist simultaneously in a solution is viewed as carrier of chemical
information. Thus, the chemo-fluidic transistor couples the molecular content of the liquid with
the fluidic behavior of the system.
The combination of the chemo-fluidic transistor and the analogy between electronics and microfluidic
allowed the development of discrete basic circuits such as the logic gates AND, OR, NOT,
and their negated counterparts rendering a complete computation. By consequently following the
electronic paradigm more sophisticated modules are demonstrated such as an RS flip-flop or a
chemo-fluidic oscillator circuit. The chemo-fluidic oscillator exhibits an autonomous oscillation in
flow rate and concentration. The system architecture and circuitry allows a decoupling of the excitation
stimulus and the emission concentration enabling future biological and medical application.
This work discusses a novel concept for the implementation of microfluidic integrated circuits. Main
aspects are examined such as technological requirements, the theoretical background, the signal
variability and biological application of the system.
Schlagwörter
-
Berichtsjahr
2017