This Small Business Technology Transfer (STTR) Phase I project is to investigate innovative approaches and provide a research-based foundation for developing a reliable and versatile wall-climbing machine that can scale odd surfaces (with deep cracks, ledges), carry large payload of testing equipment, reach hard-to-access places to carry out various non-destructive testing/evaluation (NDT/NDE) tasks to ensure the sustainability of human-built infrastructure. The technical innovations include: 1) new drivetrain using foam tread and a rotor package which not only produce strong adhesion but also helps to eliminate the acoustic/vibration interference between the climbing robot and impact-echo measurements; 2) the fault tolerance feature of multiple chamber seals in the drivetrain that allows the robot to cross deep gaps without loss of adhesion; 3) the differential drive locomotion using two drivetrains enables the robot to carry much larger payload of testing equipment; 4) the combination of impeller
and propeller provides a means for the robot to cope with ledges and allows re-attachment with the wall if the robot accidentally loses contact; 5) the use of tether helps the distribution
of payload among cable and robot adhesion mechanism and enhances the operation reliability.<br/><br/>The broader impact/commercial potential of this project is that it allows inspections of human-built infrastructure to be performed significantly faster and more thorough at a lower cost by eliminating the use of scaffolds. It also improves safety by removing the need for inspectors 
to scale high-rise buildings/structures to perform exterior inspections. In addition to visual inspection of surface flaws, the climbing machine will be able to detect subsurface defects (i.e., cracks, delamination, voids) using other NDT instruments such as impact-echo devices or ground penetrating radar (GPR). A group of such wall-climbing robots can do the inspection task simultaneously while avoid the scaffolding, thus saving time and money, making the national civil infrastructure more secure. New York City and many other cities in the world have laws that mandates the facade inspection of high-rise buildings 
every 5 years. The aging infrastructure and residential apartments lower than 6 stories in
 USA and around the world also have strong needs for inspection and property maintenance. Considering the number of buildings to be inspected every 
year, and over millions of buildings, bridges and tunnels in the country and around the world that require continuous maintenances and inspection, the market of the wall-climbing robot technology 
is vast.