Generation of Controllable Gradients in Cell Density

Making the grad(ient): A gradient in cell density was generated on a substrate that was inserted into a homogeneous suspension of cells at a specific tilt angle by taking advantage of the gradual change in the number of cells available for sedimentation (see scheme). Reverse gradients were also fabricated on the same substrate using multiple sedimentation procedures. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.