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 Tampere University of Technology. The advanced microinjection system includes two micromanipulators, a microinjector, a vision system and a control system. The control system comprises 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 an impedance measurement device and a user interface which provide information on the detection of the capillary–membrane 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.