E-Mail IMAGE: Schematic of bubble membrane showing the influence of membrane stiffener and membrane softener in the phospholipid packing. view more Credit: Amin Jafari Sojahrood and Al C. de Leon If you were given "ultrasound" in a word association game, "sound wave" might easily come to mind. But in recent years, a new term has surfaced: bubbles. Those ephemeral, globular shapes are proving useful in improving medical imaging, disease detection and targeted drug delivery. There's just one glitch: bubbles fizzle out soon after injection into the bloodstream. Now, after 10 years' work, a multidisciplinary research team has built a better bubble. Their new formulations have resulted in nanoscale bubbles with customizable outer shells -- so small and durable that they can travel to and penetrate some of the most inaccessible areas in the human body.