Micropumps operated by swelling and shrinking of temperature-sensitive hydrogels

Abstract

This paper describes two types of polymeric micropumps based on the temperature-sensitive hydrogel poly(N-isopropylacrylamide). The gel actuators are realised as photopolymerised patterns and microgels. They are electrothermically controlled by resistive heating elements. The diffusion-based micropump contains a photopatterned monolithic actuator, which is placed within the pump chamber, and provides a valveless single layer set-up. The diffusion micropump is intended for low performance applications and can operate in two modes: peristaltic or pulsatile. The maximum operating parameters are a flow rate of 2.8 +/- 0.35 microl min(-1) and a back pressure of 1.28 kPa. The second type, a displacement pump, provides a higher performance (maximal 4.5 microl min(-1) and 15 kPa). The pump comprises a microgel-based actuator, which is placed within a separate actuator layer, and active microvalves. The specific features of the design and performance of the pumps are discussed.

Diffusion and interaction in PEG-DA hydrogels

“…In technical applications, hydrogels serve as basic building blocks for gel electrophoresis or size exclusion chromatography, etc. Moreover they are nowadays implementet as "intelligent" chemo-mechanical materials using them as stimuli-responsive sensor-actor systems [1] based on their high sensitivity to environmental conditions [2] such as pH [3,4], temperature [5], solvent composition [3], light or pressure [2]. In biological contexts, hydrogels have become ideal model systems for tissue matrices due to their similarity to the extra-cellular matrix (ECM).…”

Highly Magneto-Responsive Elastomeric Films Created by a Two-Step Fabrication Process

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] For these purposes, various actuation principles have been adopted including electrostatic, 2,3,6 thermal 4,14 or piezoelectric. 1,7 However, these methods present diverse limitations, making difficult their direct utilization in the final devices.…”

Smart Microfluidics: The Role of Stimuli- Responsive Polymers in Microfluidic Devices

“…Therefore, they can be easily integrated on lab-on-a-chip devices. (Richter et al, 2009) Nestler and co-workers reported a micropump chip that employed a hydrogel based on poly(acrylic acid) sodium salt (PAAS) for generating gas molecules by electrolysis. As almost no heat is generated by electrolysis, this pumping principle is well suited for proteinsensing applications.…”