Exhibit 99.1

to

Schedule 13G

Joint Filing Agreement

The undersigned persons agree and consent to the joint filing on their behalf of this Schedule 13D dated April 9, 2010 in connection with their beneficial ownership of Memsic Inc., and any amendments thereto. Each of Ameriprise Financial, Inc. and RiverSource Investments, LLC authorizes Seligman Spectrum Focus (Master) Fund to execute the Schedule 13D to which this Exhibit is attached and make any necessary amendments thereto.

Ameriprise Financial, Inc.

By:	/s/ Wade M. Voigt Wade M. Voigt
	Director — Fund Administration

Seligman Spectrum Focus (Master) Fund

By:	/s/ Paul Goucher Paul Goucher
	Authorized Person

RiverSource Investments, LLC

By:	/s/ Paul Goucher
	Paul Goucher
	Assistant Secretary