Success with haptics using cheap ultrasonic transmitters?

[TomGeorge]

@bfinio

However, when I move my hand around over the transmitters, I feel absolutely nothing on my skin. I also tried turning the 40kHz signal on and off with 100ms delays because I read that a pulsing signal was easier to feel than a continuous one, but still nothing.

I don't think you would feel air pulses that are 40,000 pulses per second.
Even pulsing the 40kHz train would not make any difference.

Tom....