We present an array of micro artificial muscles developed for investigation of cells response to mechanical strain. Few technologies can be used to realise this type of study. However, in most cases a compromise is required and one must choose between high throughput and small population or single cell study. We previously reported the development of a device based on electro active polymer actuators which overcomes this limitation. Preliminary results however suggested a limited lifetime and some strain non-uniformity across the artificial muscles array. A new generation of devices was fabricated and the packaging was optimized in order to facilitate its use for biological experiments. Ion implanted electrodes were replaced by polymer-based electrodes in order to minimize their stiffening effect and to increase the strain uniformity. In addition, the device lifetime was studied in more detail. Multiple devices were tested in both normal working condition (with a cell culture medium covering the top side of the artificial muscle array) and air. This contribution aims to present a more comprehensive study of the device strain uniformity and lifetime. The latest advances in the device fabrication process and packaging will also be expounded.