Various technologies for treating wounds with light have been developed. When a wound is exposed to light at a specific wavelength, collagen molecules at the wound interface can be crosslinked, allowing the wound to be closed without conventional sutures or tissue adhesives.

This technique is known as photochemical tissue bonding, or PTB. Light can also regulate cellular metabolism and inflammatory responses, thereby promoting rapid tissue repair through a process known as photobiomodulation, or PBM.

These approaches are attractive because they may reduce scarring and the need for invasive procedures. The challenge, however, is how to deliver therapeutic light. Conventional phototherapeutic systems generally rely on externally powered devices such as LEDs, lasers, optical fibers and batteries. Wearing bulky or tethered equipment for extended periods is particularly difficult on highly visible areas such as the face.