Two photon polymerization involves spatial and temp oral overlap of photons to initiate chemical reactions, which lead to photopolymerization of photosensitive materials within well - defined volumes. [l ] A large variety of inexpensive photosensitive materials (e.g., polymers and Ormocer® materials) may be pro cessed with two photon polymerization. Two photon polymerization can be performed in a conventional manufacturing environment; no cleanroom facilities are needed. We have previously used two photon polymerization to create microneedles, tissue engineering scaffolds, and other medical devices. An indirect rapid prototyping approach known as two photon polymerization - micromolding has also been used to create tissue engineering scaffolds and microneedles. In this study, tissue barbs were prepared out of an ac rylate - based polymer using two - photon polymerization - micromolding ; details on the approach and the results can be found in Boehm et al.