This document discusses, among other things, an inductive component that can include a core having two portions: a first portion composed of a first material having a first magnetic saturation level; and a second portion composed of a second material selected to provide inductance for the inductive component when an external magnetic field is greater than the first magnetic saturation level. The sheath includes a cavity for housing the pointed needle or spike that extends out from the combination tool, and a cavity for at least partially encircling the body of the tool. The invention may advantageously be used to enhance implantation of embryos in the uterus, for example, in IVF treatments. The anode can is tapered on the top and oval in cross section for fitting optimally in the bony part of the ear canal. Since the etch stop layer may be formed in a repeatable way and is common across all the devices on a wafer, considerable uniformity is achieved in heater height. And, the diffraction grating becomes stable regardless of the temperature variance, and fast response time and good gray scale are achieved.