Transparent and conductive nanomembranes with orthogonal silver nanowire arrays for skin-attachable loudspeakers and microphones

Abstract

Nanomembranes and nanowires build tiny, transparent loudspeakers and sensitive, voice-recognition microphones that attach to skin.

Multiscale Soft–Hard Interface Design for Flexible Hybrid Electronics

“…In addition, the hybrid nanomembranes composed of an orthogonal AgNW network and ultrathin parylene-C films were found to have an intimate contact with human skin. [199] The bending stiffness of the hybrid nanomembranes was only 5.51 GPa µm 4 due to their nanoscale thickness, which offered a high flexibility with the smallest bending radius of ≈2.2 µm. As evidenced in Figure 13f,g, the soft hybrid nanomembranes showed high conformability with a human finger, enabling the design of a skin-attachable loudspeaker and a wearable transparent microphone.…”

“…[198] The integrated system with both the electrodes and the interconnects could be bent (>180°) and stretched (50%), allowing noninvasive thermal imaging and electroencephalography studies for the long term (>2 weeks) under dynamic environment with high recording quality. [198] Other structural designs such as fibrous gold thin films [36] and orthogonal AgNW arrays [199] are also attractive for skin-attachable electronics. Specifically, a substrate-free electronic skin was fabricated using a water-dissolvable PVA nanofiber structure deposited with gold.…”

“…Reprinted/adapted from ref. [199]. © The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science.…”

Flexible Hybrid Electronics for Digital Healthcare

“…Flexible acoustic electronics operating in the audible frequency range (20 Hz–20 kHz) include functions for detecting human acoustic signals and generating accessible sound. The former functionality refers to flexible sound sensors, or microphones, which are used in the monitoring of heart sounds, speech sounds, pulse waves, and auxiliary hearing . In 2006, an epidermal mechanoacoustic sensor for cardiovascular diagnosis was developed based on soft, strain‐isolating core/shell packaging assemblies of a microelectromechanical system (MEMS)‐based accelerometer and other components, as shown in Figure a .…”

“…Graphene, silver nanowires, liquid metal, and ferroelectric nanogenerators can also be used. There is a kind of conductive nanomembrane with an orthogonal silver nanowire array for flexible loudspeakers and microphones . As a loudspeaker, the membrane has enhanced performance in terms of thermoacoustic capabilities without any significant heat loss from the substrate.…”