Once researchers can figure out how to replace images more quickly (a pulsed laser is being considered), these images will look better as they are enlarged. Peyghambarian says that the new polymer must be made in pieces at least one square foot (929 square centimeters) before most people will take notice. The next step would be making a polymer that can display multicolored 3-D images.
Taken together, in the near future these developments could allow doctors to use the film to render three-dimensional images of the body (in green, for example) and highlight (in red) tumors and other serious medical conditions for analysis prior to surgery. Likewise, military leaders will be able to consult portable 3-D holographic maps of battlefields that automatically update as new intelligence becomes available.
Once the challenges of image replacement speed and resolution are met, home electronics makers will have what they need to create displays that can store an entire 3-D movie or video game—maybe even several—thus banishing today's much-coveted flat-panel TVs to the guest room or basement.
Holograms will also be used increasingly as sensor devices that change image and color when introduced to different stimuli. Take the hydrogel-based holograms made by Smart Holograms, a company spun out from the Institute of Biotechnology at the University of Cambridge in England. These holograms are part of the company's hand-held syringe system that measures water content in aviation fuel—necessary because excess moisture of more than 30 parts water to fuel can block aircraft fuel supply systems and stall engines during flight. The holograms react automatically when exposed to different stimuli—a gelatin-based substance in the hologram either swells or contracts in the presence of liquid, depending upon the concentration of water. Smart Holograms is also developing sensors that use holograms to alert diabetic patients and their doctors to dangerous glucose levels.
Emerging holographic and hologramlike technologies also promise to help physicians more precisely guide cancer treatments within their patients. In particular, Actuality Medical, Inc., in Bedford, Mass., is developing volumetric 3-D display devices that use data from computed tomography (CT) scans and other three-dimensional data to create lifelike computer renderings of portions of the body that doctors can study from different angles as though it were the real thing. These include the PerspectaRAD, a device that combines cancer-treatment software, a volumetric 3-D display and a haptic (or touch-based) interface that enables health care workers to visualize the location of a tumor and map out a treatment that minimizes damage to healthy tissue as well as ongoing development of the PerspectaSeed 4-D for treating prostate cancer and the MammoSolve for breast lumpectomy. "Think of this," says company CEO Michael Goldstein, "as GPS for the surgeon."