Mich. Comp. Laws § 450.2525

Sec. 525. Unless prohibited by the articles of incorporation or bylaws, action required or permitted to be taken under authorization voted at a meeting of the board or a committee of the board may be taken without a meeting if, before or after the action, all members of the board then in office or of the committee consent to the action in writing or by electronic transmission. The written consents shall be filed with the minutes of the proceedings of the board or committee. The consent has the same effect as a vote of the board or committee for all purposes.