1. Introduction

2. The context of the new fiber positioner
2.1. The DESI project

3. Mechanical requirements

4. The positioner concept design
4.1. The mechanical design
4.2. Control electronics
4.3. Communication solution
4.4. Collision avoidance algorithm

5. 4mm DC-brushless motors performance
5.1. Backlash and repeatability
5.2. Power consumption
5.3. Current consumption control

6. Positioner testing set-up

7. Results
7.1. Accuracy measurements
7.2. Backlash characterization

8. Conclusions