Reseachers from Tokyo university-Japan have made a technology that projects images on screen made of soap film.
The whole idea is based on the common knowladge that soap bubble is a micro membrane and when light passes through it, the colour in its structure is displayed. The membrane screen is controlled using ultra sonic vibrations. On the other hand the reflective property is modified by changing the wave frequency.
(http://news.bbcimg.co.uk/media/images/61299000/jpg/_61299218_9db4f365-f66f-49e9-90fc-1478f4ec9c81.jpg)
This system plays a major contribution to open up a new path for display engineering with sharp imageries, transparency, BRDF(Bidirectional Reflectance Distribution Function) and flexibility.
3D or Holographic projection effects are achieved by putting togather several bubble screens.
ref: bbc