Precision pen height control for micro-scale direct writing technology

An apparatus for precision pen height control, the apparatus comprising:

• a dispensing member, a portion of the dispensing member defining an opening;
• a fluid dispensing system, the fluid dispensing system being in fluid communication with the opening by a tubular member;
• a vertical position sensing system fixedly engaged to the tubular member, the vertical position sensing system comprising a diffraction grating and an optical grating sensor, the optical grating sensor being positioned adjacent the diffraction grating, the optical grating sensor being constructed and arranged to sense the diffraction grating, the diffraction grating being engaged to a vertical support, the vertical support being engaged to the tubular member, the optical grating sensor being further constructed and arranged to produce a vertical position signal based upon the position of the vertical support;
• and
• a linear actuator fixedly engaged to the tubular member by the vertical support of the vertical position sensing system, the linear actuator being engaged to the vertical position sensing system, the linear actuator constructed and arranged to receive a control signal generated at least partially from the vertical position signal, the linear actuator constructed and arranged to produce and apply vertical forces to the vertical support in response to the control signal.

An apparatus for precision pen height control, the apparatus comprising:

• a dispensing member, a portion of the dispensing member defining an opening;
• a fluid dispensing system, the fluid dispensing system being:
• in fluid communication with the opening by a tubular member;
• a vertical position sensing system fixedly engaged to the tubular member, the vertical position sensing system comprising a diffraction grating and a sensor, the sensor being positioned adjacent the diffraction grating, the sensor being constructed and arranged to sense the diffraction grating, the diffraction grating being engaged to a vertical support, the vertical support being engaged to the tubular member, the sensor being further constructed and arranged to produce a vertical position signal based upon the position of the vertical support;
• and
• a voice coil motor fixedly engaged to the tubular member by the vertical support of the vertical position sensing system, the voice coil motor being engaged to the vertical position sensing system, the voice coil motor constructed and arranged to receive a control signal generated at least partially from the vertical position signal, the voice coil motor constructed and arranged to produce and apply vertical forces to the vertical support in response to the control signal.