Method of electrochemically producing hydrogel, method of producing hydrogel with pattern formed of cells, hydrogel production apparatus, and transducer
A hydrogel is formed by a reaction which is induced, in an electrolytic solution, by an electrode product electrochemically generated by electrodes installed in the electrolytic solution. An apparatus including an electrolytic tank with a bottom surface on which a two-dimensional array of working electrodes is provided and a counter electrode installed in the electrolytic tank is prepared. An electrolytic solution containing a dissolved substance that causes electrolytic deposition of a hydrogel is housed in the electrolytic tank. By applying a predetermined voltage to one or more selected working electrodes of the two-dimensional array, a hydrogel with a two-dimensional pattern corresponding to the arrangement of the selected working electrodes is formed.
1. A method of electrochemically producing a hydrogel by using an apparatus for electrolytic deposition of the hydrogel, the apparatus including: an electrolytic tank having a bottom surface; an electrolytic solution housed in the electrolytic tank and containing a solute for the electrolytic deposition of the hydrogel; working electrodes arranged two-dimensionally on the bottom surface of the electrolytic tank; and a counter electrode placed in the electrolytic solution, the method comprising:
applying a first predetermined voltage to one or more of the working electrodes to form, on the bottom surface of the electrolytic tank, the hydrogel having a two-dimensionally defined pattern corresponding to an arrangement of the one or more of the working electrodes, the forming of the hydrogel being progressed by a reaction caused in the electrolytic solution by an electrode product electrochemically generated by the one or more of the working electrodes; and
applying, after the forming of the hydrogel by applying of the first predetermined voltage, a second predetermined voltage different from the first predetermined voltage to the one or more of the working electrodes to separate the hydrogel from the one or more of the working electrodes, the separating of the hydrogel being progressed by dissolving a part of the hydrogel contacting the one or more of the working electrodes.
2. A method of producing a hydrogel having a pattern formed of cells, the method comprising
carrying out the method according to claim 1 that uses as the electrolytic solution a suspension containing the cells and the solute for the electrolytic deposition of the hydrogel, and thereby forming, on the bottom surface of the electrolytic tank, the hydrogel having the pattern formed of the cells.
3. The method according to claim 2 further comprising
distributing densely, before the forming of the hydrogel, the cells above the one or more of the working electrodes by dielectrophoresis that is caused by applying an alternating voltage of a predetermined frequency to the one or more of the working electrodes.
4. The method according to claim 3 , wherein
the distributing of the cells by dielectrophoresis is carried out by using an electrode placed in the electrolytic solution, the electrode having an electrode plane parallel to the bottom surface and facing the working electrodes.
5. The method according to claim 3 , wherein
the distributing of the cells by dielectrophoresis is carried out by using electrodes on the bottom surface each surrounding in a non-contact manner a corresponding one of the working electrodes or using an electrode on the bottom surface having holes each surrounding in a non-contact manner a corresponding one of the working electrodes.
6. The method according to claim 2 further comprising
distributing densely, before the forming of the hydrogel, the cells above the one or more of the working electrodes by electrophoresis that is caused by applying a predetermined direct voltage to the one or more of the working electrodes.