A method of assembling a group of devices, the method comprising the steps of: creating a temporary bond between each component (108, 112) of a first group of two or more components on a source device and a transfer device, wherein creating the temporary bond between each component (108, 112) of a first group of two or more components on a source device and a transfer device comprises trapping a first local pressure in a first group of voids of the transfer device, wherein the first group of voids of the transfer device are located at positions corresponding to the positions of the first group of the two or more components (108, 112) from the source device, wherein trapping the first local pressure comprises: bringing the first group of two or more components (108, 112) from the source device into contact with the transfer device under the first local pressure; and altering the first local pressure to a second local pressure, wherein the second local pressure is higher than the first local pressure, thereby to create a pressure differential between the first local pressure trapped in each of the first group of voids of the transfer device and the second local pressure, wherein the strength of the temporary bond created by the pressure differential is sufficient to selectively remove the first group of components (108, 112) from the source device; separating the transfer device and the source device, thereby selectively removing the first group of two or more components (108, 112) from the source device whilst the transfer device is temporarily bonded to each component (108, 112) of the first group of two or more components on the source device; positioning the first group of two or more components (108, 112) on a host device; and decoupling the first group of two or more components (108, 112) from the transfer device, thereby to form a first group of assembled devices. creating a temporary bond between each component (108, 112) of a first group of two or more components on a source device and a transfer device, wherein creating the temporary bond between each component (108, 112) of a first group of two or more components on a source device and a transfer device comprises trapping a first local pressure in a first group of voids of the transfer device, wherein the first group of voids of the transfer device are located at positions corresponding to the positions of the first group of the two or more components (108, 112) from the source device, wherein trapping the first local pressure comprises: bringing the first group of two or more components (108, 112) from the source device into contact with the transfer device under the first local pressure; and altering the first local pressure to a second local pressure, wherein the second local pressure is higher than the first local pressure, thereby to create a pressure differential between the first local pressure trapped in each of the first group of voids of the transfer device and the second local pressure, wherein the strength of the temporary bond created by the pressure differential is sufficient to selectively remove the first group of components (108, 112) from the source device; bringing the first group of two or more components (108, 112) from the source device into contact with the transfer device under the first local pressure; and altering the first local pressure to a second local pressure, wherein the second local pressure is higher than the first local pressure, thereby to create a pressure differential between the first local pressure trapped in each of the first group of voids of the transfer device and the second local pressure, wherein the strength of the temporary bond created by the pressure differential is sufficient to selectively remove the first group of components (108, 112) from the source device; separating the transfer device and the source device, thereby selectively removing the first group of two or more components (108, 112) from the source device whilst the transfer device is temporarily bonded to each component (108, 112) of the first group of two or more components on the source device; positioning the first group of two or more components (108, 112) on a host device; and decoupling the first group of two or more components (108, 112) from the transfer device, thereby to form a first group of assembled devices.