4-bit digital liquid lens for variable focal length

We present 4-bit digital liquid lens for variable focal length using the binary control of four bit actuators (b₄, b₃, b₂, and b₁ actuators). The input volume into the lens is precisely controlled in 2⁴ levels depending on the binary control of the bit actuators such as digital actuation mode (b₄b₃b₂b₁). Compared to previous analog liquid lens, it precisely control lens curvature and focal length. Experimentally, the maximum deflection range of the present lens is 0~11.6 mum and one step of maximum deflection, least significant bit (LSB), is 0.75 mumplusmn0.2 mum. It also control focal length from 3.63 to 38.6 mm in 16 levels.