  We present ab initio calculations which show that the direct-band-gap,
effective masses and Fermi velocities of charge carriers in ZnO monolayer
(ML-ZnO) in graphene-like honeycomb structure are all tunable by application of
in-plane homogeneous biaxial strain. Within our simulated strain limit of $\pm
10$%, the band gap remains direct and shows a strong non-linear variation with
strain. Moreover, the average Fermi velocity of electrons in unstrained ML-ZnO
is of the same order of magnitude as that in graphene. The results promise
potential applications of ML-ZnO in mechatronics/straintronics and other
nanodevices such as the nano-electromechanical systems (NEMS) and
nano-optomechanical systems (NOMS).

Mesoscale and Nanoscale Physics;Materials Science