THIS WORK WILL DEVELOP A NOVEL ELECTROSTATIC MICROSTRUCTURED GECKO LIKE ADHESIVE THAT WILL DEMONSTRATE AN ORDER OF MAGNITUDE IMPROVEMENT OF ELECTROSTATIC ADHESION PRESSURE COUPLED WITH THE UNIQUE ABILITY TO SHED DUST PARTICLES. THE INCREASE IN ADHESION PRESSURE WILL DIRECTLY IMPROVE APPENDAGE MECHANISMS FOR DOCKING AND PERCHING FOR THE ASTROBEE SPHERES CLASS OF FREE FLYING ROBOTS ON SMOOTH SURFACES ROUGH SURFACES AND EVEN FABRICS. THE LATTER TWO ARE MADE POSSIBLE BY COMBINING THE BENEFITS OF MICROSTRUCTURED AND ELECTROSTATIC ADHESION IN ONE DEVICE. FURTHERMORE THE DUST MITIGATION CAPABILITIES HAVE THE POTENTIAL TO TRANSITION MICROSTRUCTURED ADHESIVES FROM LABORATORY EXPERIMENTS THAT REQUIRE FREQUENT CLEANING BY HAND TO FLIGHT CAPABLE SYSTEMS. ELECTROSTATIC ADHESION WORKS BY CREATING AN ELECTRIC FIELD BETWEEN TWO OPPOSITELY CHARGED ELECTRODES SEPARATED BY A DIELECTRIC. THESE ELECTRODES TYPICALLY LIE SIDE BY SIDE ON THE SAME PLANE. OUR APPROACHS INNOVATION IS TO MOVE THESE ELECTRODES TO DIFFERENT PLANES. THIS ALLOWS US TO INCREASE THE VOLTAGE AND USE SMALLER GAPS BETWEEN THE ELECTRODES. BOTH GAP SIZE AND VOLTAGE HAVE A QUADRATIC RELATIONSHIP TO ADHESION PRESSURE. THUS THE NEW DESIGN AS SHOWN VIA SIMULATIONS CAN YIELD UP TO 20 TIMES MORE ADHESION PRESSURE THAN OUR CURRENT DESIGN. MOREOVER THE NEW LAYERED APPROACH ALLOWS US TO EMPLOY A TRAVELING WAVE WHICH THROUGH TRIBOELECTRIFICATION CAN REPEL AND MOVE DUST PARTICLES OFF THE MICROSTRUCTURED PORTION OF THE ADHESIVE. THIS WORK COULD LEAD TO DRAMATIC IMPROVEMENTS AT THE SYSTEM LEVEL IN SEVERAL WAYS. FIRST OVERALL INCREASED ADHESION LEVELS WILL IMPROVE SYSTEM PERFORMANCE AND ALLOW FREE FLYING ROBOTS TO EXERT HIGHER INERTIAL LOADS DURING DOCKING OR PERCHING MANEUVERS. SECOND INCREASED ELECTROSTATIC ADHESION LEVELS WILL IMPROVE A FREE FLYING ROBOTS ABILITY TO ADHERE TO NON SMOOTH SURFACES. CURRENT MICROSTRUCTURED ADHESIVES DO NOT PERFORM WELL ON SUCH SURFACES. OUR PREVIOUS WORK DEMONSTRATED THAT COMBINING AN ELECTROSTATIC ADHESIVE WITH A MICROSTRUCTURED ADHESIVE SIGNIFICANTLY IMPROVES ADHESION ON ROUGHER SURFACES AND EVEN ALLOWS ADHESION TO FABRICS. LAST THE ABILITY TO SHED THE ADHESIVE OF SMALL DUST PARTICLES WOULD SIGNIFICANTLY IMPROVE THE RELIABILITY OF GRIPPERS FOR FREE FLYING ROBOTS. DUST MITIGATION IS ARGUABLY THE MOST DIFFICULT TECHNOLOGICAL CHALLENGE ASSOCIATED WITH DRY ADHESION AND NO RESEARCH TO DATE HAS EVELOPED A PRACTICAL SCALABLE GECKO LIKE ADHESIVE THAT IS EVEN REMOTELY ROBUST TO DIRT PARTICLES. OUR PROPOSED DESIGN HAS THE POTENTIAL TO ADDRESS THIS PROBLEM THUS ALLOWING REPEATED USAGE WITHOUT THE NEED FOR HUMAN INTERVENTION.
$271,221FY2016National Aeronautics and Space AdministrationNASA
Illinois Institute Of Technology, Chicago IL