Biotechnology, information, and medical industries have high growth potential. A key technology for those industries is the replication of micro- and nanostructures. Precise micro-and nanostructured parts with functional surfaces can be produced economically by injection molding. The whole process chain (thermal mold condition, molding, demolding, measurement, and analysis) must be analyzed carefully to ensure the highest accuracy and reliability. To enable the precise production of such structures, a new technique for variothermal injection molding was developed at the IKV. An innovative laser heating unit was developed, designed, and built. In experiments the laser unit was analyzed and implemented into an injection mold to heat the cavity surface efficiently. Using this technique selective parts of the cavity could be heated with high temperature gradients of up to 300 degrees C/s. Preliminary measurements were done to correlate the laser power and the temperature change on the mold surface. A pyrometer and a laser control unit were implemented and realize a precise temperature profile on the mold surface and avoid a temperature overshoot.