Programmable encoder paired with piezo motors provides exceptionally high resolution to observe minute amounts of light in DNA sequencing application.

The Challenge

The science of genomics deals with mapping the DNA of living organisms. The benefits of this technology are applied to various fields such as human biomedical research, plant and animal biology, microbiology, and infectious disease research. One company’s automated sequencing system utilizes a unique technology which actually observes minute amounts of light generated by the natural process of DNA replication. This technology required extremely precise sample positioning under the light detection optics in an environment with very stable temperature.

The Solution

The Mercury™ II programmable encoder family was paired with a piezo motor stack for the fine positioning of a six axis (hexapod) stage. The encoder provided the customer with exceptionally high resolution with low pass noise filtering, integrated end of travel limit signals, and low power dissipation in the head as well as customized sensor cables for ease of installation. During measurement, the hexapod motors are turned off so position stability is of crucial importance.

The Benefit

The Mercury II Series optical (non-contact) encoder operates on a 20um pitch diffraction scale with integrated index and left/right limit marks. With up to 16,384x interpolation it boasts a user programmable resolution between 5um and 1.22nm. External digital interpolation keeps the power dissipation in the sensor head low and a digital low pass input filter provides excellent position stability by rejecting high frequency noise sources.


Sensor Dimensions32.0 x 13.5 x 8.7mm
InterfaceDigital A-quad-B with index and limits
Grating Dimensions15.0 x 6.0 x 2.5mm (index and limits included)
Grating Period20µm
System Resolution1.22nm
Maximum Speed48.8 mm/sec
Sensor Weight6g