A microchip fabricated with a vapor-diffusion self-assembled-monolayer method to transport droplets across superhydrophobic to hydrophilic surfaces

Yu Hsuan Lai, Jing Tang Yang, Dar Bin Shieh

Research output: Contribution to journalArticlepeer-review

72 Citations (Scopus)

Abstract

A wettability gradient to transport a droplet across superhydrophobic to hydrophilic surfaces is fabricated on combining a structure gradient and a self-assembled-monolayer (SAM) gradient. The combination of these two gradients is realized with a simple but versatile SAM technique, in which the textured silicon wafer strip is placed vertically in a bottle that contains a decyltrichlorosilane solution to form concurrently a saturated SAM below the liquid surface and a wettability gradient above. The platform fabricated in this way has a water-contact angle from 151.2° to 39.7°; the self-transport distance is hence increased significantly to about 9 mm. A theoretical model that approximates the shape of a moving drop to a spheroidal cap is developed to predict the self-transport behavior. Satisfactory agreement is shown for most regions except where the hysteresis effect is unmeasurable and an unsymmetrical deformation occurs. A double-directional gradient surface to alter the direction of movement of a droplet is also realized. The platforms we developed serve not only to transport a fluid over a long distance but also for a broad spectrum of biomedical applications such as protein adsorption, cell adhesion and DNA-based biosensors.

Original languageEnglish
Pages (from-to)499-504
Number of pages6
JournalLab on a Chip
Volume10
Issue number4
DOIs
Publication statusPublished - 2010

All Science Journal Classification (ASJC) codes

  • Bioengineering
  • Biochemistry
  • Chemistry(all)
  • Biomedical Engineering

Fingerprint Dive into the research topics of 'A microchip fabricated with a vapor-diffusion self-assembled-monolayer method to transport droplets across superhydrophobic to hydrophilic surfaces'. Together they form a unique fingerprint.

Cite this