title: Design and fabrication of a passive droplet dispenser for portable high resolution imaging system.
abstract: Moldless lens manufacturing techniques using standard droplet dispensing technology often require precise control over pressure to initiate fluid flow and control droplet formation. We have determined a series of interfacial fluid parameters optimised using standard 3D printed tools to extract, dispense and capture a single silicone droplet that is then cured to obtain high quality lenses. The dispensing process relies on the recapitulation of liquid dripping action (Rayleigh-Plateau instability) and the capturing method uses the interplay of gravitational force, capillary forces and liquid pinning to control the droplet shape. The key advantage of the passive lens fabrication approach is rapid scale-up using 3D printing by avoiding complex dispensing tools. We characterise the quality of the lenses fabricated using the passive approach by measuring wavefront aberration and high resolution imaging. The fabricated lenses are then integrated into a portable imaging system; a wearable thimble imaging device with a detachable camera housing, that is constructed for field imaging. This paper provides the full exposition of steps, from lens fabrication to imaging platform, necessary to construct a standalone high resolution imaging system. The simplicity of our methodology can be implemented using a regular desktop 3D printer and commercially available digital imaging systems.
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Tahseen
authors.initials: T
authors.lastname: Kamal
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Rachel
authors.initials: R
authors.lastname: Watkins
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Zijian
authors.initials: Z
authors.lastname: Cen
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia.
authors.forename: Jaden
authors.initials: J
authors.lastname: Rubinstein
authors.affiliation: Plant Biosecurity Cooperative, Research Centre, LPO Box 5012, Bruce, ACT 2617, Australia.
authors.forename: Gary
authors.initials: G
authors.lastname: Kong
authors.affiliation: Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 2601, Australia.|Australia Research Council Centre of Excellence in Advanced Molecular Imaging, Australian National University, Australia.
authors.forename: Woei Ming
authors.initials: WM
authors.lastname: Lee