Scalable Manufacturing of Solderable and Stretchable Physiologic Sensing Systems

Abstract

Methods for microfabrication of solderable and stretchable sensing systems (S4s) and a scaled production of adhesive-integrated active S4s for health monitoring are presented. S4s' excellent solderability is achieved by the sputter-deposited nickel-vanadium and gold pad metal layers and copper interconnection. The donor substrate, which is modified with "PI islands" to become selectively adhesive for the S4s, allows the heterogeneous devices to be integrated with large-area adhesives for packaging. The feasibility for S4-based health monitoring is demonstrated by developing an S4 integrated with a strain gauge and an onboard optical indication circuit. Owing to S4s' compatibility with the standard printed circuit board assembly processes, a variety of commercially available surface mount chip components, such as the wafer level chip scale packages, chip resistors, and light-emitting diodes, can be reflow-soldered onto S4s without modifications, demonstrating the versatile and modular nature of S4s. Tegaderm-integrated S4 respiration sensors are tested for robustness for cyclic deformation, maximum stretchability, durability, and biocompatibility for multiday wear time. The results of the tests and demonstration of the respiration sensing indicate that the adhesive-integrated S4s can provide end users a way for unobtrusive health monitoring.

All‐in‐One, Wireless, Stretchable Hybrid Electronics for Smart, Connected, and Ambulatory Physiological Monitoring

“…ECG-derived heart rate (HR) and respiratory rate (RR) along with the onboard motion sensor provide valuable and critical set of physiological information without compromising device's formfactor. [24,25] Details of the fabrication process are described in the Supporting Information ( Figure S1 and Note S1), and the description of the circuit design and the chip components can be found in the Supporting Information ( Figure S2 and Table S1). Since a skin-conformal, low-modulus elastomer has shown negligible skin irritation, [19,20] three gold ECG electrodes are integrated with the elastomer substrate to allow the formation of a gapless electrode-to-skin interface and obviate the need for the use of conductive gels.…”

All-Painting Process To Produce Respiration Sensor Using Humidity-Sensitive Nanoparticle Film and Graphite Trace

“…Respiration rate is one of the vital signs and directly relates to the condition of respiratory organs. In order to detect respiration rate remotely, several types of portable respiration sensors have been proposed [10][11][12][13][14][15][16][17] . Colloidal nanomaterial films are promising as a humidity-sensitive film to detect respiration 18,19 .…”

Fully portable and wireless universal brain–machine interfaces enabled by flexible scalp electronics and deep learning algorithm

“…First, using microfabrication processes, the thin-film flexible circuit boards were constructed on a polydimethylsiloxane (PDMS)-coated four-inch silicon wafer and peeled-off for subsequent steps. 49 The details of this process are given in Section S1. Second, the surface mount chip components were soldered onto exposed copper pads by reflow soldering using a solder paste (SMDLTLFP10T5, Chip Quik).…”