Embedded servo controller for Picus electronic pipette & Liquid handling

When Biohit set some really challenging targets to their upcoming new hand held servo motor controlled pipette, Picus, it was clear that a high tech partner in embedded motor controls was needed in order to meet the strict technical requirements in the given schedule.

The main use of electronic pipettes is to speed up precision liquid dispensing and mixing in laboratories. Electronic pipettes are based on motor manipulated piston where strict safety and repeatability requirements set extreme challenges to the motor controller inside the device. Other major challenges are restrictions in physical size, weight, battery life as well as low BOM cost.

Granite Devices Inc was called up to provide the source code level solution for the servo motor control implementation in addition to the board level hardware design solutions. The outcome was fully embedded servo controller consisting of only few physical components while servo algorithms run inside a low power 8 bit microcontroller.

 

Sartorios Picus pipette

Several innovations were made to achieve the high goals set by the application:

  • Miniature DC servo motor control fully running on pipette's low power Atmel XMEGA microcontroller
  • Maximum dynamic motor performance gained by cascaded current controller and feed-forward controllers
  • Predictive electromechanical piston brake control to achieve micro liter dispensing repeatability as well as fast stopping of piston to cut the liquid flow without dripping

Sartorius Biohit Liquid Handling

Biohit is known as the forerunner in liquid handling products with a long history in developing ergonomic, high quality pipettes. Biohit Liquid Handling is part of Sartorius, one of the world's leading providers of laboratory and process technologies and equipment. Biohit's new flag ship product, Picus electronic pipette, has already won two design awards: the Red Dot Design Award 2012 and the Fennia Prize Honorary Mention 2012. Picus has set a new standard for electronic pipettes.

Ville Hintikka, Chief Designer

Granite Devices

Granite Devices is known from cost efficient embedded servo and stepper motor controls. Granite Devices offers several motor control stock products as well as embedded motion control engineering services.

Tero Kontkanen, Custom Solutions Leader