Generation of Tunable Aerosol Droplet Sizes for Novel Hand-held Inhaler

<p dir="ltr">Personalised Airway and Lung Management (PALM) is a novel hand-held inhaler that can produce personalised aerosols for highly effective pulmonary drug delivery for the treatment of respiratory diseases such as asthma. Modal and harmonic response analyses have been conducted on a silicon chip containing multiple high aspect ratios etched microchannels to determine the mode shapes and deflections. One of the fundamental modes is used in computational fluid dynamics (CFD) simulations as a boundary condition. That mode resembles the vertically oscillatory motion described by the Mathieu equation. Furthermore, the formation and stability of capillary waves at the liquid free surface can be illustrated by the stability chart. The microfluidic chip is vibrated at high frequencies to control the diameter of the ejected droplets. CFD simulations of the PALM device showed that the onset of aerosolisation occurs at four times the theoretical critical amplitude as expected in the literature and the PALM device can produce narrow size distribution of aerosol droplets.</p>