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TTN200645-D02
PCS-6000 Series Motorized Patch-Clamp Micromanipulator
Chapter 3: Description
Chapter 3 Description
3.1.
Mechanisms of Motion
PCS-6000 linear stages integrate piezo-flexure assemblies inside crossed roller
bearing linear stages with a stepping motor for coarse motion. The joystick is
used to control the coarse motion. A large knob on the Axis Control Unit ( ACU)
controls the fine positioning obtained by use of a piezo. Two rotary pivot stages
are incorporated into the manipulator to allow optimum adjustment of the pipette
working angle and easy pipette exchange.
3.1.1. Coarse Motion
Coarse motion is provided by a stepping (servo) motor attached to the linear
translation stage. The motor is controlled by a joystick that has a “dead zone” in
the rest position. This is a safety feature so that a small accidental touch does
not cause motion. The farther away from the neutral position the joystick is
moved, the faster the motor moves the stages. The direction of motion of the
motor is controlled by the direction of the joystick motion. It is possible to move
along a diagonal line if the joystick is moved along a diagonal.
With practice, an operator can learn to position the pipette within ~15
μm
of the
target with the coarse motion provided by the motor.
3.1.2. Fine Motion
The piezo-flexure stages integrated into the linear stage provide fine motion.
These stages contain a piezoelectric ceramic element that expands when a
voltage is applied across it. The piezoelectric element is mounted in a specially
machined metal body that provides amplification of the motion.
Figure 3–1 Section View of Stage and Piezo Showing the Additive Nature
The voltage applied to the piezoelectric ceramic element is controlled by the
position of the large knob on the ACU. The large knob is connected to a three-
turn potentiometer (variable resistor). The expansion of the piezoelectric ele-
ment is determined solely by the position of the knob. Thus, the motion of the
stage follows the position of the knob. The motion is instantaneous and stops as
soon as the knob is left in a single position.
