Effect of Micropillar Characteristics on Leidenfrost Temperature of Impacting Droplets

When a liquid droplet gets in contact with a surface at a temperature above the Leidenfrost temperature, the part of the droplet in contact with the surface vaporizes creating an insulating vapor layer that keeps the droplet levitating. In this study, the effects of the width, height to width and pitch to the width of the Si micro pillar on Leidenfrost temperature and boiling characteristics are investigated. The difference of dynamic LFP between surface with micro pillar and unprocessed silicon was −25K to 80K. And that of nominal LFP was −10 to 90K. It was observed that the micro pillars could control the temperature range of the transition boiling region and transition film boiling region. This transition has been observed to be broader than the one corresponding to the plain silicon surface.