  The ability to individually manipulate the increasing number of qubits is one
of the many challenges towards scalable quantum information processing with
trapped ions. Using micro-mirrors fabricated with micro-electromechanical
systems (MEMS) technology, we focus laser beams on individual ions in a linear
chain and steer the focal point in two dimensions. We demonstrate sequential
single qubit gates on multiple $^{171}$Yb$^+$ qubits and characterize the gate
performance using quantum state tomography. Our system features negligible
crosstalk to neighboring ions ($< 3\times 10^{-4}$), and switching speed
comparable to typical single qubit gate times ($<$ 2 $\mu$s).
