Capillary pressure microinjection of living adherent cells: challenges in automation

This paper is divided into two parts. The first part describes the current status and the general challenges of developing automatic microrobotics systems for microinjection of adherent mammalian cells. The discussion covers applications and the review and challenges of the components of a capillary pressure microinjection system: a micromanipulator, a microinjector, a microcapillary, a vision system and an environment control system. The second part of the paper describes the research performed on the automatic capillary pressure microinjection at the Tampere University of Technology. The advanced microinjection system includes two micromanipulators, a microinjector, a vision system and a control system. The control system comprises of motion control schemes for the micromanipulators to accurately position a microcapillary, to precisely penetrate a cell membrane and to deliver information on the injection to the operator. A novel injection guidance system being part of the control system comprises of an impedance measurement device and a user-interface which provide information on the detection of the capillarymembrane contact, capillary clogging and capillary breakage. Results show a remarkable increase of the injection success from 40 % to 65 % when the injection guidance system is used.