Till Photonics has introduced the VoiceCoil, a fast microscope z-drive. It combines the range of a stepper motor-driven coarse drive (22mm) with the precision of a piezo at an exceptional speed. Accuracy of 20nm pp is available at full range, thus enabling 3D scans of unprecedented quality. Settling time for a 2μm step is 10ms allowing z-stacks, which are only limited by the speed of the camera.
A voice coil drive works similar to a dynamic loudspeaker where the coil is moving the membrane of the speaker. In Till's VoiceCoil the membrane is replaced by the microscope objective. Here, however, a very precise optical position measurement system with a closed loop feedback ensures nanometre precise position control of the objective. The VoiceCoil z-drive will be used in Till's digital microscope iMIC.
