In consideration of the ubiquity of swift particles in space environment, understanding the effects of ion irradiation on the adhesion force and mechanical properties of multi-walled carbon nanotube arrays is significant to apply the arrays as adhesive materials in space in the future. In this study, multi-walled carbon nanotube arrays prepared through chemical vapor deposition were irradiated by He2+ under different fluences and then characterized via multiple methods. The arrays were severely damaged when the fluence reached or exceeded 1 x 10(16) cm(-2). As the fluence increased, more amorphous carbons were generated from their original position in the carbon nanotubes. The adhesion force quickly decreased when the irradiation fluence rapidly increased, which limited the service life of the arrays as adhesive materials. Finally, the instantaneous modulus of the multi-walled carbon nanotube arrays initially increased and then decreased when the fluence increased because of the different contact modes between the indenter and the samples. (C) 2017 Elsevier B.V. All rights reserved.