Wafer-scale design of lightweight and transparent electronics that wraps around hairs

Abstract

Electronics on very thin substrates have shown remarkable bendability, conformability and lightness, which are important attributes for biological tissues sensing, wearable or implantable devices. Here we propose a wafer-scale process scheme to realize ultra flexible, lightweight and transparent electronics on top of a 1-mm thick parylene film that is released from the carrier substrate after the dissolution in water of a polyvinyl-alcohol layer. The thin substrate ensures extreme flexibility, which is demonstrated by transistors that continue to work when wrapped around human hairs. In parallel, the use of amorphous oxide semiconductor and high-K dielectric enables the realization of analogue amplifiers operating at 12 V and above 1 MHz. Electronics can be transferred on any object, surface and on biological tissues like human skin and plant leaves. We foresee a potential application as smart contact lenses, covered with light, transparent and flexible devices, which could serve to monitor intraocular pressure for glaucoma disease.

High-performance giant magnetoresistive sensorics on flexible Si membranes

“…30 Smaller bending radii can be achieved by using thinner flexible foils. 6,20,31 As indicated in Fig. 1(d), the local deformation in the bent Si membrane is considered to increase linearly with the distance from the central neutral mechanical plane, which itself remains unstrained (tensile strain towards the outside and compressive towards the inside).…”

Contact resistance and overlapping capacitance in flexible sub-micron long oxide thin-film transistors for above 100 MHz operation

“…5 Different forms of silicon, 6,7 carbon based materials like nanotubes or organic polymers and small molecules, [8][9][10] or amorphous semiconductors can be used to build such devices. 11,12 Deformable wireless sensors or bendable radio frequency transceivers require electronic circuits which operate in the megahertz regime in order to treat signals, and transmit data. The basic components of all these flexible circuits are thin-film transistors (TFTs) who should be optimized to achieve sufficient electrical and mechanical performance using cost effective fabrication methods.…”

Biomimetic Microelectronics for Regenerative Neuronal Cuff Implants

“…[ 12 ] The active electronic devices are fabricated on a polyimide support capping a hydrogel-based stimuli-responsive layer. The swelling state of the hydrogel can be affected by tailoring the environmental conditions, including solution composition and pH.…”

“…Although mechanically adaptive to the environment, these soft actuators do not carry active electronics to assess and communicate the environmental changes. Alternatively, there are ultrathin and lightweight mechanically fl exible and even imperceptible electronics, [9][10][11][12] which are electrically active but lack of reversible self-actuation. outgrowth of neural stem cells from the cortex region of E14 mouse embryonic brains in the channels formed by the microtubes ( Figure 1 d and Figure 2 ).…”