Fascinating use of vibrational frequencies to induce a virtual sense of feeling for an artificial limb. The illusion is referenced as vibration-induced kinesthetic illusion and has been in use for over 40 years. What is different is the application for amputees to sense artificial limbs. The following study (published in the Journal of Science Translational Medicine) is informative on many levels:
http://stm.sciencemag.org/content/10/432/eaao6990
On the positive side, this technology can be used for patients with impaired feeling and/or loss of feeling in existing limbs. Further, the potential is for a person to "feel" and/or control a robotic arm / device remotely using vibrational frequencies as an extension of haptic feedback for a variety of applications. There are many challenges with controlling remote devices and/or equipment when only relying on instrumentation and visual feedback. The addition of virtual "feelings" can add significant new capabilities to overcome these limitations.
On the negative side, anyone introducing foreign vibrational frequencies into someone without their consent, could impart virtual control over another person. This would be a kinesthetic hack and presents a whole new dimension of risk (threat if you will to our security - on a much more personal level). A discussion for a future posting.