Mixed-Reality CellBidirectinal coupling between real and virtual bio-oscillator

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Interface Device

As it’s listed above, the interface device aims at making the communication between the virtual part and real part possible and keep cells alive during long time observation. For the first one, light is chose to be the media because of its specialty of physics as well as ability of influencing organism. For the last one, based on former studies, cells cultivated on a microfluidic chip proved to be helpful. After all the matters have been solved, we should go on for the whole design of device. The first step of our project is the bidirectional influence between virtual and real so that connection between them can be divided into two parts as the diagram below, Light Receiving which is from the real part to the virtual part and Light Controlling which is the opposite of it.

1 Light Receiving part

In this part, we are working on keeping cells alive and making them well detected by computer. The design is that cells are cultivated on a microfluidic chip which is put on an inverted fluorescence microscope. The CCD camera connected with microscope can get real-time snapshots of observed cells and the computer can transfer them into data of fluorescence intensity. Eventually, the Light Receiving part have passed the oscillations of real part from cells to virtual part. And then, it can connect with the data processing procedure in the computer.

1.1 Microfluidic chip

Microfluidic chips (Lab-on-chip technologies) originated from analytical chemistry and adopt sophisticated technologies to make micro-channels about several square centimeters on chip. This technology integrates sample’s injection, separation and detection into a signal chip.

Why do we choose microfluidic chip among so many tools?

1) It’s rapid, high efficiency and low consumption.

2) With a syringe pump, it can precisely control the flowing rate of fresh and warm medium to provide a steady environment for bacterium.

3) Chambers of chip can trap bacterium in a fixed position so that the fluorescence intensity of cells can be captured by fluorescence microscope easily.

4) There are numerous chambers in one micro-channel and two channels in one chip which leads to a large number of repeated experiments in the same time.

The design of our chip

*1. Two kinds of chambers

There are two kinds of chambers, one is a square room with 30nm height while another looks like a swimming pool with 15nm depth and 30nm width. After cells and medium are injected into micro-channels, parts of cells can be trapped in chambers proliferating freely and chambers will be full of cells in about 3 hours while superfluous cells are squeezed out chambers.

*2. Three inlets and one outlet

As is shown below, our microfluidic chip is made up of three media inlets and a waste outlet while the green arrow points to waste outlet and the blue arrow points to media inlet. The media inlet 1, 2, 3 is used to inject fresh medium IPTG and arabinose respectively and the outlet is for discharging the effluent and injecting bacterial solution.

插入图片

1.2 Inverted fluorescence microscope

For the real-time observation of fluorescence intensity, a fluorescence microscope is needed. In the same time, for a clear vision of a single chamber, the chip have to be observed with 100x oil lens which means that the lens may almost touch the chip. Thus, with four transparent pipes on the chip, it seems to be inconvenient by normal fluorescence microscope but inverted one is perfect.

Inverted fluorescence microscope is made of fluorescent accessories and inverted microscope, and mainly used in the observation of living organisms. As a result of these living detected objects are placed in a culture dish or bottles, it requires a long working distance between objective lens and condenser lens for direct observation. Therefore, the position of the objective lens, condenser and the light source are reversed. And also, a CCD camera is connected with the microscope so that we can get real-time photos and even a video during observation.

2 Light Controlling part

In this part, we are working on transferring the information from the virtual part to the real part. A microcontroller and several LED light beads are used to achieve this goal. Specifically speaking, after analyzing two oscillators, the computer will change parameters in its own oscillator as well as the illumination intensity of LED as you can see in the modeling part. And then, a USB line is used to pass the command from the computer to a microcontroller which are able to control the illumination intensity of LED directly. Based on all of these, the oscillator of cells can be controlled which means that the information flowing from the virtual part to the real part achieved. The core of the Light Controlling part is programs on the microcontroller to communicate with both the computer and LED light beads. As you can see at the Project Page, we have divided our finally goal into three phases and the target as well as program for interface device at phase 2 and 3 is almost the same. Hence, the details and design scheme of program will be put in the Mixed-reality between physics part.

3 Current progress in interface device