On the attenuation of ultrasound by pure black tattoo ink

Abstract

Black tattoo ink comprises hydrophobic carbon black nanoparticles. We hypothesized that black tattoo ink demonstrates transient dynamic activity in an ultrasound field. Brightness-mode sonography was performed on cylindrical receptacles of different bore diameters, filled with black tattoo ink, water, saline, or air, using pulsed ultrasound with center frequencies of 13 MHz and 5 MHz.The scattering from black ink itself lasted less than ten minutes. At 13-MHz sonication, a transient drop in sound speed was observed, as well as a transient lessening of scattering from distal phantom tissue. The linear acoustic attenuation coefficient of pure black ink was measured to be 0.15±0.01 dB cm −1 MHz −1 , equal to whole blood.Low-intensity ultrasonic tattoo removal would be of interest as an alternative to techniques that damage surrounding tissue.

Nucleation threshold of carbon black ultrasound contrast agent

“…24) The linear resonance frequencies of these suspended nanoparticles were estimated to be greater than 15 MHz. 24) In a recent feasibility study, we found that carbon black pigment dispersion under sonication demonstrates transient nucleation. 26) In this follow-up study, we investigated the nucleation threshold of carbon black pigment dispersion nanoparticles both theoretically and experimentally.…”

“…23) In solid state, it comprises nanoparticles or nanoparticle aggregates with a mode diameter of 0.24 μm and a maximum diameter of 0.97 μm. 24) In solution, a hydrophobic particle takes up its own volume plus a surrounding void. 25) Consequently, in solution, the carbon black pigment dispersion nanoparticles or aggregates thereof were measured to have a mode diameter of 0.29 μm and a maximum diameter of 1.14 μm.…”

“…25) Consequently, in solution, the carbon black pigment dispersion nanoparticles or aggregates thereof were measured to have a mode diameter of 0.29 μm and a maximum diameter of 1.14 μm. 24) In carbon black dispersion, the gaseous void surrounding the hydrophobic solid nanoparticle takes up approximately 20% of the diameter. 24) The linear resonance frequencies of these suspended nanoparticles were estimated to be greater than 15 MHz.…”

“…24) In carbon black dispersion, the gaseous void surrounding the hydrophobic solid nanoparticle takes up approximately 20% of the diameter. 24) The linear resonance frequencies of these suspended nanoparticles were estimated to be greater than 15 MHz. 24) In a recent feasibility study, we found that carbon black pigment dispersion under sonication demonstrates transient nucleation.…”

Rapid tablet swelling and disintegration during exposure to brightness-mode ultrasound

“…∞) and therefore at which . Following the method for computation of time-dependant speed of sound of a nucleating medium of known initial size, 33) the speed of sound of the disintegrating tablet was subsequently computed using where c ⊖ (t) is the instantaneous speed of sound in the tablet and is the perceived distance to the coin surface. Throughout the experiments, gas bubbles were observed to accumulate on the transducer surface.…”