Kaori Kuribayashi

Electroformation of giant liposomes in microfluidic channels

This paper describes a method to produce giant liposomes in microfluidic channels. To prepare the liposomes, we have investigated two different methods: electroformation and conventional gentle-hydration. We found that the liposomes produced by the conventional method were relatively small size, and several liposomes were enclosed inside another liposome. On the other hand, the liposomes formed by electroformation were mostly giant liposomes and did not enclose liposomes inside. Using microfluidic channels with electroformation method, we have succeeded in enclosing different types of the nano/micro materials into giant liposomes in the same microfluidic device simultaneously.

Artificial flagellates: Analysis of advancing motions of biflagellate micro-objects

This paper describes an analysis of advancing motions of micro-objects with two flagella separated from a unicellular alga, Chlamydomonas reinhardtii. We harnessed their flagella as actuators of the micro-objects. The isolated flagella can be attached to microbeads and propel them. We found that the biflagellate beads tend to advance, while the uniflagellate microbeads only rotate. Our model for the motion of the biflagellate beads led to conditions for generating an advancing motion. This approach is important since it provides general guidelines for designing micro-objects driven by flagellalike actuators.

Electroformation of solvent-free lipid membranes over microaperture array

We propose a method of the preparation for solvent-free lipid membranes over an array of micrometer-sized apertures from patterned lipid films using electroformation. We utilize micro-patterned Parylene masks to generate this array of micro-patterned lipid membranes over the array of apertures. By micropatterning the surface in this manner, we form uniformly-sized dome-shaped bilayers.

Sequential parylene lift-off process for selective patterning of biological materials

This paper describes a method of selective patterning of various types of biological materials with parylene lift-off process. Multiple parylene thin sheets with a microhole array were formed on a glass substrate, and were then sequentially peeled off during the pattering process. Using this method we have achieved high density patterning of different kinds of beads, lipids and proteins on the same substrate, respectively. We have also patterned proteins on a parylene sheet, and rolled up the sheet to a cylindrical structure as a demonstration of 3D protein chips.

Flexible organic leds with parylene thin films for biological implants

This paper describes an ultra thin, flexible device with organic light emitting diodes (OLEDs) between Parylene thin films (20 mum or less in total thickness). The device was formed on a glass substrate and could be easily peeled off without breaking. The OLEDs in the flexible device emitted light with high brightness, and were useful as excitation light sources for fluorescent dyes. We have also demonstrated a flexible probe with an OLED for the application of biological implants toward in vivo fluorescent imaging and optical stimulation of cells.

Arraying Single Adherent Cells by Microplate Self-Assembly

This paper describes a method for handling a single adherent cell using a self-assembly technique. We produce microplates using Parylene with both hydrophilic and hydrophobic sides. We culture the cells on the hydrophilic side, and utilize the hydrophobic side to self-assemble the plates onto the hydrophobic regions. Culturing a single cell on each Parylene microplate facilitates their handling since we can manipulate them as floating cells, and easily relocate them without the loss of cellular activity. In our experiment, we assemble 50 ¿m circle microplates with adherent cells in an array.

“Artificial flagellates” selective attachment of flagella as a bioactuator of micro-object

We propose a method for attaching flagella to a selected region of a micro-object. We separated the flagella of unicellular algae Chlamydomonas from their body and reactivate them by adding adenosine triphosphate (ATP). We fixed them on a specific region of micro-scale beads using a device that has a perforated Parylene sheet separating a flagella solution from a no-flagella one. We have succeeded in attaching flagella to 5 μm-diameter beads. After that, we observed various behaviors of the beads attached with flagella: rotation, oscillation, and advancing motion like that of the Chlamydomonas. We believe that flagella can be utilized as bioactuators for various micro devices.

A selective release method using electrolytically generated bubbles for cell array applications

This paper describes a method of selective release of particles/cells by bubbles generated by electrolysis. The particles/cells trapped into microchambers that were produced with SU-8 on the top of an electrode of indium tin oxide (ITO) patterned on glass. The bubbles of oxygen and chlorine (or hydrogen) were selectively generated in a target chamber by applying voltage through the electrodes. We successfully released a microbead (100 µm in diameter) confined in the microchamber. Since this method is gentle enough to maintain the cellular activity, we believe that this method will be useful for quantitative analysis of cells in a microarray.