Centimeter-Height 3D Printing with Femtosecond Laser Two-Photon Polymerization

Nowadays 3D printing has been widely used for producing geometrically complex 3D structures from a broad range of materials such as ceramics, metals, polymers and semiconductors. Although it has been demonstrated that a fabrication resolution as high as ≈100 nm can be achieved in 3D printing based on two-photon polymerization (TPP), the end product height of TPP is typically on millimeter scale limited by the short working distance of high-numerical-aperture focal lens. Herein, a method based on simultaneous spatiotemporal focusing of the femtosecond laser pulses is presented, which enables fabricating centimeter-height 3D structures of fine features with TPP. An isotropic spatial resolution is also demonstrated, which can be continuously tuned in the range of ≈10–40 µm by only varying the power of femtosecond laser, making this technique extremely flexible and easy to implement. Several Chinese guardian lions of a maximum height of 0.6 cm and a Terra Cotta Warrior of a height of 1.3 cm are fabricated using this method.