1.   Currently the frequencies are sorted with surface acoustic wave devices, or SAWs.

2.   Like capacitive screens, acoustic wave screens are robust.

3.   Meanwhile, Apostolos Doukas at Massachusetts General is using laser pulses to generate the acoustic waves that make the skin permeable.

4.   Now researchers have found that acoustic waves can make the skin temporarily permeable, so doctors can sample body fluids or inject medication without piercing the skin.

5.   Of course, acoustic wave physics are much more complex than that.

6.   Researchers in the United States have found that acoustic waves make the skin temporarily permeable, so doctors can sample body fluids or inject medication without piercing the skin.

7.   The sound engine could tap that thermal waste and use it to move a spring-mounted piston driven by acoustic waves.

8.   They can generate these acoustic waves using ultrasound or a shockwave from a pulsed laser.

9.   Millions of dollars have been invested to find a material that is light, stiff yet cheap and faithfully conducts acoustic waves.