Motion sensing interface has attracted leading human interaction researchers'' attention since Microsoft''s Kinect first official appearance at the 2009 Electronic Entertainment Expo. This thesis attempts to define the term, "motion sensing interface" and illustrate its applications in the realm of interactive art by introducing two interactive art works.

The first interactive art called "Space Recall" experiments the idea of revisiting the places where the traveler has visited before. By setting up cameras to record the places the traveler has been to, the work creates a stimulating environment that engages users to experience time and space in the past. The designed system has the ability to process hundreds of images of time and space with Microsoft''s Photosynth software and synth the images into one enormous panorama image. With the technical help from Microsoft''s Kinect, the cameras set on the floors can keep track of the user''s head position in real space and calculate the projected views.

The second interactive art entitled "Bind" is a laser light installation that was made to provoke discussions of human''s speed of information consumption in the digital world. It explores the consequences of being bombarded by all kinds of information. The installation illustrates the tension between information and human being by making laser lights as information, shooting the user with fast speed. The system behind the work was developed based on the conference research paper, "A Depth-Based Crowded Heads Detection System through a freely located camera". The cameras set on the ceilings will keep track of user''s head position in real space and calculate the numbers of the degrees that Laserbots'' motors need to turn. Eventually the laser lights shoot toward the users relying on the precision of body motion detection.

These two interactive art works demonstrate how different head positions can shape the way the interactive work looks. The former is an example of how different head positions can change panorama images'' perspectives. The latter illustrates how they can make changes of laser lights'' geometry and its sound effects. With different human body movements, from sensing motions to triggering interactive events, the thesis argues that motion sensing interface can become an appendage, an extended part of our bodies, and be used more intuitively.