“Our objective is adding tactile feedback to the hovering image in 3D free space. One of the biggest issues is how to provide tactile sensation. Although tactile sensation needs contact with objects by nature, the existence of a stimulator in the work space depresses the appearance of holographic images. Therefore some kind of remote- controllable tactile sensation is needed. That is achieved by our original tactile display [Iwamoto et al. 2008]. The following paper explains the technologies employed for a ‘Touchable Holography.’” Found on Siggraph 2009 via Make.