A rectangular space, i.e., a valve chamber 4, is formed in a flow channel substrate 1. Flow channels 2a, 2b, and 2c are connected to the valve chamber 4 from different directions. The flow channels 2a and 2b are connected respectively to a first surface 5a and a second surface 5b, opposite to the first surface 5a, of the valve chamber 4. The flow channel 2c is connected to a third surface 5c different from the first surface 5a and the second surface 5b.
A valve body 8 is accommodated in the valve chamber 4. The valve body 8 slides between the first surface 5a and the second surface 5b in the valve chamber 4. The valve body 8 is formed by a magnetic material such as Fe, Cu, or Ni, or resin, and a magnet or magnetic particles are buried in the valve body 8. The position of the flow channel 2c and the size of the valve body 8 are set, such that the flow channel 2c will not be closed by the valve body 8 no matter the valve body 8 moves to the first surface 5a or to the second surface 5b.
On the sides of the first surface 5a and the second surface 5b outside the valve chamber 4, electromagnets 10a and 10b serving as an electromagnetic portion are buried in the flow channel substrate 1 to sandwich the valve chamber 4.
By means of the magnetic field generated by the electromagnet 10a, the valve body 8 is moved to the surface 2a in the valve chamber 4, and by means of the magnetic field generated by the electromagnet 10b, the valve body 8 is moved to the surface 2b in the valve chamber 4.
If only the electromagnet 10a is powered, the electromagnet 10a generates a magnetic field, causing the valve body 8 to move to the surface 2a, and thus closing the flow channel 2a. At this time, the remaining two flow channels 2b and 2c are in an open state, and the two flow channels 2b and 2c are connected.
Moreover, if only the electromagnet 10b is powered, the valve body 8 moves to the surface 2b due to a magnetic field generated by the electromagnet 10b, and thus closing the flow channel 2b. At this time, the remaining two flow channels 2a and 2c are in an open state, and the two flow channels 2a and 2c are connected.
In this embodiment, by controlling the ON/OFF of the electromagnets 10a and 10b disposed on the sides of the valve chamber 4, only the flow channel 2a or 2b formed in the flow channel substrate 1 is closed, and the remaining two flow channels are connected. Therefore, the flow channels connected by the magnetic field generated by the electromagnet 10a or 10b can be switched directly, thereby having a good response. In addition, as the structure of the valve mechanism only includes the valve body 8 accommodated in the valve chamber 8 and the electromagnets 10a and 10b, the valve mechanism can be directly embedded in the flow channel substrate 1 without adding complexity to the structure of the flow channel substrate 1.
Here, in this embodiment, the electromagnets 10a, 10b are configured to sandwich the flow channel substrate 1. Further, it is also possible to allow the electromagnets 10a, 10b to generate magnetic fields in the direction that the valve body 8 slides. For example, as shown in
In addition, another embodiment of the valve mechanism embedded in the flow channel substrate will be described.
A flow channel 16 is formed in a flow channel substrate 11. The flow channel substrate 11 is formed by overlapping a PDMS substrate 14 on a glass substrate 12. A rectangular space, i.e., a valve chamber 18, is formed in the middle of the flow channel 16. The valve chamber 18 is formed on the PDMS substrate 14 by pressing, and the PDMS substrate 14 in the portion where the valve chamber 18 is formed is thinner than in other portions. The thin portion of the PDMS substrate 14 forms a wall 22 of the valve chamber 18. As shown in
An electromagnet 24 is disposed below the glass substrate 12, in which the electromagnet 24 functions as an electromagnetic portion that generates a downward magnetic field. If the downward magnetic field is generated in the valve chamber 18, the magnet 20 buried in the wall 22 causes the wall 22 to bend and meanwhile moves to the side of the glass substrate 12, such that the wall 22 contacts the glass substrate 12.
In other words, as for the valve mechanism of this embodiment, if the electromagnet 24 is powered, under the effect of the downward force of the magnetic field generated by the electromagnet 24, the magnet 20 causes the wall 22 to bend and meanwhile moves towards the side of the glass substrate 12. Thus, after the valve chamber 18 obstructs the flow channel 16, the flow channel 16 is closed. When a voltage is not applied on the electromagnet 24, the bent wall 22 is restored to the state shown in
Thus, the valve mechanism of this embodiment can control the opening/closing of the flow channel 16 by controlling the ON/OFF of the electromagnet 24. Accordingly, the valve mechanism also directly controls the opening/closing of the flow channel 16 with the electromagnet 24, and a good response is resulted. In addition, as the valve mechanism includes the valve chamber 18, the magnet 20, and the electromagnet 24 driving the magnet 20, the structure of the flow channel substrate 11 will not become complicated. The valve chamber 18 has the wall 22 formed by a deformable material such as PDMS etc., and the magnet 20 is buried in the portion that forms the wall 22 of the PDMS substrate 14.
In this embodiment, the magnet 20 is buried in the portion that forms the wall 22 of the PDMS substrate 14. However, the present invention is not limited to the above, and the magnet 20 can also be mounted above the portion that forms the wall 22 of the PDMS substrate 14.
In addition, in this embodiment, the restoring force of PDMS is used to turn the flow channel 16 from a close state to an open state. However, the present invention is not limited to the above. The electromagnet can also be disposed above the PDMS substrate, and an upward magnetic field generated by the electromagnet can be used to enable the magnet 20 buried in the wall 22 to move upward. In addition, a spring mechanism can also be mounted, and the elastic force of the spring can be used to open the flow channel 16.
Number | Date | Country | Kind |
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2006-127318 | May 2006 | JP | national |