Digital Smell: Toward Electrically Reproducing Artificial Smell Sensations

Artificially reproducing smell sensations, without using chemical odorants, would change the future multisensory internet experiences. This article presents a computer-controlled smell reproduction technology proposed for stimulating human olfactory receptors, using weak electric pulses. We developed a concept prototype that can generate rectangular-shaped weak electrical pulses in different frequencies (0–30 kHz), duty cycles (0–100%), and currents (1–5 mA). This prototype is tested by stimulating the middle nasal concha region of 31 healthy human participants. During our studies, 8 participants reported chemical and fragrant smell sensations for the stimulation parameters 1 mA with 70 Hz. For 1 mA with 10 Hz, 8 participants reported sweet smell sensation, while 6 participants reported chemical smell sensations. The key novelties of this paper include: 1. describe the development of the first computer controlled digital device for stimulating the olfactory receptor neurons, 2. Testing this new technology on human subjects including the parameters that were not previously tested, 3. Recording the intensities for 22 types of sensations (smell-related and non-smell-related) that could be produced by the electrical stimulation. 4. investigate users’ perception on the usefulness of this type of technology.