Bernoulli grip explained

A Bernoulli grip uses airflow to adhere to an object without physical contact.[1] Such grippers rely on the Bernoulli airflow principle. While an accelerating, increasing speed, airstream has a low downstream static pressure, the sharp turn from linear to radial flow is the cause of a region of very low pressure around the blower exit hole. This is the cause of a net force on the object in the direction normal to the side with higher local pressure. A Bernoulli gripper takes advantage of this by maintaining this negative pressure at the gripper face compared to the ambient pressure below the sample, while maintaining an air gap between the gripper and the object being held.

Applications

Commercially available Bernoulli grips are commonly used to handle rigid sheet like material such as silicon wafers in circuit board manufacturing, or photovoltaic cell components.[2] [3] Since the grip is contactless, this form of gripping lends itself to handling sterile material to prevent chemical and/or biological contamination. Research has been done into using Bernoulli grippers to transport sample sheet foodstuffs in a food processing context,[1] although this work found difficulties as the flexible foods would vibrate against the gripper, deforming and alternately blocking the gripper and/or being blown away from the airway.The Bernoulli grip is also being investigated as a non-contact adhesion mechanism for wall climbing robots.[4]

Notes and References

  1. Web site: Airflow (Bernoulli) Grippers for Flat Sheet Foods . Food Refrigeration & Process Engineering Research Centre, The Grimsby Institute of Further & Higher Education . 25 May 2011.
  2. Brun . X.F. . Melkote . S.N. . 2006 IEEE 4th World Conference on Photovoltaic Energy Conference . Evaluation of Handling Stresses Applied to EFG Silicon Wafer using a Bernoulli Gripper . George W. Woodruff Sch. of Mech. Eng.; Georgia Inst. of Technol., Atlanta, GA . May 2006 . 1346–1349 . Waikoloa, HI . 10.1109/WCPEC.2006.279680 . 1-4244-0017-1 .
  3. Web site: Osborne . Mark . New Product: Bernoulli Gripper from Festo enables 'contactless handling' . PVTech . 8 February 2010 .
  4. Web site: Ackerman . Evan . Robot Uses Supersonic Jets of Air to Stick to Almost Anything . IEEE Spectrum . 24 May 2011 . 25 May 2011.