Abstract: A nail trimmer apparatus (and related methods). The apparatus is a small handheld battery powered device that safely trims nails by leveraging unique physical properties of the skin and nail tissue. A trimming action is driven by a compact motor of appropriate speed and torque and a mechanism that converts the rotation of the motor shaft to an oscillating action at the head. A cushioned abrasive surface attached to the head oscillates with a frequency and stroke that optimizes the trimming of the nail while not adversely affecting surrounding skin. By selecting a desirable form factor and trimming properties, the device is particularly well suited to trimming infant's nails. Infant's nails are often difficult to trim due to the small size of the finger or toe and nail, the lack of cooperation by the infant and the precision required by existing nail trimming tools. The simple one-handed trimmer does not generally require significant dexterity and can be used whether the infant is asleep or awake.