Fig. 1: Schematic illustration of optical microlens fabrication using liquid shaping technique.
a(i) Production of microlens on a wettability-modified substrate using a piezoelectrically actuated dispenser with thermal control. a(ii) Ultrasmall OCT microendoscope based on liquid-shaped microlens for in vivo imaging in small and convoluted luminal organs, such as coronary vasculature. b, c Schematic of optical liquid on a substrate (without physical boundary). The microlenses of the same liquid volume (V1) on the substrates of different wettability (W1 - W3) have a different radius, i.e., r1 - r3, and contact angle, i.e., θ1 - θ3 (b). As the liquid volume increases from V1 to V3 on the substrate of the same wettability W4, the radius of microlens increases from r4 to r6 while maintaining a contact angle of θ4 (c). d Production of spheroid microlens using a substrate with a circular boundary. The radii and contact angles of microlenses made with different liquid volumes are indicated with r1, r2, and θ1, θ2, θ3, respectively. e Fabrication of ellipsoid microlens on a substrate with an elliptical boundary. The semi-major length, i.e., m1, m2, m3, semi-minor length, i.e., n1 and n2, contact angle on x-z plane from θx1 to θx3, and contact angle on y-z plane from θy1 to θy3 of the microlenses are illustrated when different liquid volumes are used on the substrate. Please note that n1 = m1, n2 = m2, θx1 = θy1, and θx2 = θy2.
