Substrate‐Free Transfer of Large‐Area Ultra‐Thin Electronics

Abstract

Innovation in materials and technologies has promoted the fabrication of thin‐film electronics on substrates previously considered incompatible because of their chemical or mechanical properties. Indeed, conventional fabrication processes, typically based on photolithography, involve solvents and acids that might harm fragile or exotic substrates. In this context, transfer techniques define a route to overcome the issues related to the nature of the substrate by using supportive carriers in the electronics stack that mitigate or avoid any damages during the fabrication process. Here, a substrate‐free approach is presented for the transfer of ultra‐thin electronics (<150nm‐thick) where no additional layer besides the electronics one remains on the final substrate. Devices are transferred on several surfaces showing good adhesion and an average performance variation of 27%. Furthermore, a sensor bent to a radius of 15.25µm, shows variation in performance of 5%. The technique can also be sequentially repeated for the fabrication of stacked electronics, enabling the development of ultra‐thin devices, compliant on unconventional surfaces.

Application of Stone-Derived Substrates in Thin-Film Temperature Sensing

“…Using linear ohmic behavior, the average resistances of thermistors fabricated on marble, brick, stone paper, and Limex substrates were determined to be 63 kΩ, 125 kΩ, 400 kΩ, and 1 kΩ, respectively, at room temperature. These values are comparable to those published previously for thin-film thermistors fabricated on Si, polyimide, glass, and polished alumina substrates [17], [40], [41]. Resistance variations of the thermistors in response to temperature changes while heating and cooling from 25 • C to 80 • C were observed through five cycles.…”

“…Furthermore, there is great potential in exploring unconventional and novel substrates, which can either have the electronics directly fabricated onto them or receive it from a donor substrate through transferring techniques [17]. Besides offering important characteristics, such as recyclability [18] or biodegradability [19], stretchability [20], unconventional substrates can also bring functional properties like self-healability [3], and permeability [21], thereby enriching the application possibilities, as the sensor can be fabricated onto a wide range of materials, such as thin-foils and larger objects [22].…”

Multiscale Transfer Printing via Shape Memory Polymer with High Adhesion and Modulus Switchability

“…Consequently, the intervention of chemical solutions could lead to sample surface contamination and the wet etching process incurs significant time costs. 34 Mechanical-assisted transfer printing technology is a dry process that could steer clear of contamination from chemical solutions and produce rapidly. For these reasons, researchers have explored various methodologies to modulate interface adhesion, including kinetically controlled transfer printing, 29,39 stimuli-responsive transfer printing, 40−45 laser-driven transfer printing, 46,47 and bioinspired transfer printing.…”

“…Generally, an elastomeric stamp is attached to the surface of the pattern which is on a rigid donor substrate, and then pick the pattern up to finish the transfer process . Afterward, the elastomeric stamp is attached to a flexible receiver substrate and print the transferred pattern. , Researchers have developed various transfer printing technologies to enhance the stability of the patterning process, including sacrificial layer-assisted transfer printing − and mechanical-assisted transfer printing. − When it comes to the sacrificial layer-assisted transfer printing technology, wet etching could not be avoided to remove the sacrificial layer, which was added between pattern and donor substrate to weaken the interface adhesion for successful transfer. Consequently, the intervention of chemical solutions could lead to sample surface contamination and the wet etching process incurs significant time costs .…”