Photolithography‐Based Microfabrication of Biodegradable Flexible and Stretchable Sensors (Adv. Mater. 6/2023)

Abstract

Microfabrication of Biodegradable Sensors In article number 2207081, Levent Beker and co‐workers report a photolithography‐based microfabrication process for bioresorbable devices. Consecutive application of sacrificial, adhesion and protection layers enable the use of delicate conductive and insulating bioresorbable materials through standard microfabrication processes. Using this approach, high‐density passive electric components and chemical sensors critical for transient electronics and implant applications are developed.

Dry‐Transferable Photoresist Enabled Reliable Conformal Patterning for Ultrathin Flexible Electronics

“…[11] Miniaturization, flexibility, and conformally adhering to human skin while maintaining their electrical features are significant factors that determine the functionality of flexible devices. [11,12] Realizing flexible electronic systems with these factors depends on the ability to perform scalable patterning of electronic materials on unusual substrates via various fabrication approaches, such as inkjet printing, [13] laser ablation, [14] and 3D printing. [15,16] The main limitation of these fabrication approaches is their lack of spatial resolution, making them incompatible with multiscale and massproduction device microfabrication.…”

“…[38,39] In addition, the capability of wafer-level and high-throughput fabrication makes photolithography economically practical, thereby enabling highly integrated circuit manufacturing. [12] Unfortunately, conventional photolithographic fabrication processes cannot accommodate the micro/nanofabrication of flexible devices because of the use of unusual substrate topologies and uneven surfaces, as well as damage to organic substrates by solvents and thermal loading, which affect device performance, including sensitivity, stability, and consistency. [12,24,39] For instance, photolithography requires a rigid substrate, such as silicon or glass, which limits the ability of the resulting devices to bend or stretch.…”

“…[12] Unfortunately, conventional photolithographic fabrication processes cannot accommodate the micro/nanofabrication of flexible devices because of the use of unusual substrate topologies and uneven surfaces, as well as damage to organic substrates by solvents and thermal loading, which affect device performance, including sensitivity, stability, and consistency. [12,24,39] For instance, photolithography requires a rigid substrate, such as silicon or glass, which limits the ability of the resulting devices to bend or stretch. [21] Additionally, the organic solvent associated with photolithography can damage or delaminate the polymer substrates, leading to reduced device performance and reliability.…”

“…[21] Additionally, the organic solvent associated with photolithography can damage or delaminate the polymer substrates, leading to reduced device performance and reliability. [12,40] Dry film photoresist-based photolithography has attracted more attention in recent years due to its solvent-free operating process. However, there are still challenges for these photoresists, including volume shrinkage, limited resolution capability, and insufficient mechanical properties.…”

Templated Laser-Induced-Graphene-Based Tactile Sensors Enable Wearable Health Monitoring and Texture Recognition via Deep Neural Network

“…8,9 Previous works have demonstrated that the design of micronano structures, 10,11 such as micropyramids 12,13 and micropillars, 14,15 are beneficial in achieving high sensitivity and a broad working range. 16,17 Traditional fabrication methods for these microsensing structures, such as nanomicro composite inks, optical lithography, 11,13,18 laser ablation, 19,20 vacuum disposition, 21 3D printing, 22,23 and other techniques, tend to be costly, complex, and time-consuming. 24−26 essential to develop an effective route to fabricate tactile sensors with a high performance.…”