Figure 1.

Fabrication and implantation of micro-pigment-encapsulated biodegradable microneedles (PBMs). (a) PBMs are fabricated in two phases of (i) unpigmented primary layer, and (ii) micro-pigment-encapsulated secondary layer. Briefly, the unpigmented droplet is dispensed over a thin hyaluronic acid (HA) sheet and centrifuged to form a wine glass-shaped primary layer. The micro-pigment-encapsulated droplet is then dispensed over the solidified primary layer and centrifuged to form PBMs. (b) Upon complete implantation, PBMs reside in the dermis layer and reduce the contrast between scalp and hairs. (c) A microscopic image of a 5 × 5 PBM array. (d) PBMs are fabricated over flexible biodegradable sheets that can be washed off post-implantation. (e) Top view of the bent PBM-fabricated flexible sheet.