TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The semiconductor epilayer is a gallium nitride layer including indium gallium nitride, gallium nitride, aluminum gallium nitride, gallium nitride:magnesium, gallium nitride:silicon, gallium nitride:aluminum nitride and gallium nitride:zinc oxide. The growth substrate is sapphire. The adhesion layer is gold, aluminum, aluminum, palladium, indium, nickel, polyurethane, polyimide and/or silicone. The sacrificial layer comprises silicon oxide, aluminum arsenide, silicon nitride, zinc oxide, aluminum nitride, hafnium nitride or aluminum indium nitride. The handle substrate comprises silicon, silicon carbide, silicon nitride, fused silica, alumina, zirconium oxide, magnesium oxide, pyrolytic boron nitride, aluminum nitride, aluminum silicate and titania. The selective etchant is hydrochloric acid, hydrogen fluoride, phosphoric acid, potassium hydroxide, tetramethylammonium hydroxide, ethylenediamine, pyrcatechol, hydrazine chelating amines, 1,2-diaminoethane and sodium hydroxide. The conductive material comprises a conductive paste consisting of silver epoxy, gold epoxy, copper epoxy and/or aluminum epoxy. The anisotropic etchant is potassium hydroxide or tetramethylammonium hydroxide.    TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The multilayer comprises LED device layers including contact layers, spreader layers, cladding layers and barrier layers, and p-type gallium nitride layer in electrical contact with an n-type gallium nitride layer. The gallium nitride layers correspond to a vertical type gallium nitride LED. The step of bonding the first contact surface of the semiconductor epilayer to the handle substrate comprises contacting the first contact surface of the semiconductor epilayer to an external surface of the handle substrate so as to establish Van der Waals bonding between the semiconductor epilayer and the handle substrate. The external surface of the handle substrate has an adhesion layer. The step of partially releasing the semiconductor epilayer from the growth substrate comprises a partially removing a sacrificial layer provided between the growth substrate and the semiconductor epilayer. The sacrificial layer is removed by photoelectrochemical etching or dissolving. The semiconductor epilayer and the growth substrate meet at an interface in which an electromagnetic radiation from a laser or a xenon lamp is exposed through the growth substrate. The electromagnetic radiation is partially absorbed by an absorbing layer to release the semiconductor epilayer from the growth substrate. The mask comprises a first mask layer of provided on a portion of the second contact surface of the epilayer and a second mask layer of metal provided on the first mask layer. The step of removing material from the exposed regions comprises etching the exposed regions via inductively coupled plasma reactive ion etching. A step of anchoring one or more semiconductor structures to the handle substrate is carried out by one homogenous anchor or heterogeneous anchor. The semiconductor structures are transferred from the handle substrate to a device substrate via contact printing using a conformal transfer device or a poly(dimethylsiloxane) stamp. The device substrate is a glass substrate or a polymer substrate, a flexible substrate, a large area substrate, a pre-metallized substrate and/or a substrate pre-patterned with device components. The handle substrate comprises a doped or undoped semiconductor, a single crystal material, a polycrystalline material, a ceramic, a polymer, glass, quartz and/or a semiconductor with or without a thermal oxide layer. The step of removing material etches a depth into the growth substrate of 5-10 nm. The anisotropic etching occurs along (110) directions of the growth substrate, and comprises directional wet etching using an anisotropic etchant. The step of removing material from the exposed regions exposes side walls of the LED device structures by masking a portion of the side walls prior to the step of partially releasing the LED device structures from the growth substrate. A buffer layer or an etch block layer is provided between the multilayer and the sacrificial layer. The step of partially releasing comprises exposing the sacrificial layer to a selective etchant. The contact area and contact surface of the printable electronic device are aligned off center from each other, where contact between the contact surface and the contact area binds the printable electronic device to the contact surface. The electromagnetic radiation has wavelengths of 100-800 nm. The sacrificial layer is provided at an electric potential of 600-800 mV. The filling material comprises an optical material, which forms an optical element of a collecting optic, a concentrating optic, a reflective optic, a diffusing optic, a dispersive optic, a lens, a phosphor, a waveguide, an optical fiber, an optical coating, a transparent optic, an optical filter and/or a polarizing optic. A conductive material is in electrical communication with electrode contacts of the electronic device components. After curing, the conductive material has a resistivity of 1x 10-10 to 1x 10-2 Omega cm.