Fully Printed, Highly Sensitive Multifunctional Artificial Electronic Whisker Arrays Integrated with Strain and Temperature Sensors

Abstract

Mammalian-mimicking functional electrical devices have tremendous potential in robotics, wearable and health monitoring systems, and human interfaces. The keys to achieve these devices are (1) highly sensitive sensors, (2) economically fabricated macroscale devices on flexible substrates, and (3) multifunctions beyond mammalian functions. Although highly sensitive artificial electronic devices have been reported, none have been fabricated using cost-effective macroscale printing methods and demonstrate multifunctionalities of artificial electronics. Herein we report fully printed high-sensitivity multifunctional artificial electronic whiskers (e-whisker) integrated with strain and temperature sensors using printable nanocomposite inks. Importantly, changing the composition ratio tunes the sensitivity of strain. Additionally, the printed temperature sensor array can be incorporated with the strain sensor array beyond mammalian whisker functionalities. The sensitivity for the strain sensor is impressively high (∼59%/Pa), which is the best sensitivity reported to date (>7× improvement). As the proof-of-concept for a truly printable multifunctional artificial e-whisker array, two- and three-dimensional space and temperature distribution mapping are demonstrated. This fully printable flexible sensor array should be applicable to a wide range of low-cost macroscale electrical applications.

3D Printing Fiber Electrodes for an All‐Fiber Integrated Electronic Device via Hybridization of an Asymmetric Supercapacitor and a Temperature Sensor

“…Temperature sensors have emerged at the right moment to detect temperature variations and prevent the advent of disease 27, 28. Wearable temperature sensors capable of real‐time monitoring of human health‐related parameters can offer new approaches to manage the health status and performance of individuals to enable many emerging applications, such as e‐skin, smart watches, robot sensors, human–machine interfaces, health care, human activity monitoring, and environmental temperature measurement 29, 30, 31, 32. However, wearable temperature sensors have been mainly based on planar structure, and fiber‐shaped structures have rarely been reported.…”

Ultrastretchable Fiber Sensor with High Sensitivity in Whole Workable Range for Wearable Electronics and Implantable Medicine

“…The response time of the sensor was measured by application of quasitransient stretching to the sensor23 (Figure S10, Supporting Information). As shown in Figure 4 a, the sensor exhibited a response time of only 16 ms, which was much faster than recently reported values for other strain sensors (70–110 ms) 30, 36, 37. Figure 4b shows the variation of Δ R / R 0 of a strain sensor that underwent 20 000 stretch‐release cycles from 5% to 7% strain.…”

Nanomaterial‐Enabled Wearable Sensors for Healthcare

“…The temperature sensitivity was ≈0.7 Ω °C −1 over the range of RT to 50 °C. [23] Graphene [47,49,[75][76][77][78] and CNTs [79][80][81] have been widely adopted as the thermoresistive sensing elements for wearable temperature sensors. Graphene nanowalls, made of vertically aligned interlaced graphene nanosheets, were transferred onto a PDMS substrate to fabricate flexible temperature sensors (Figure 2a).…”

“…Wearable temperature and mechanical sensors (e.g., strain sensors, pressure sensors, and force sensors) have been integrated to realize wearable health and activity monitoring, human-interactive devices and multifunctional electronic skin. [47,65,80,172,196,197] An array of temperature sensors, threeaxis tactile and slip force sensors were printed onto a flexible substrate (Figure 7d) for electronic skin, where thermoresistive CNT-PEDOT:PSS composites served as flexible temperature sensors and four resistive AgNP-CNT strain sensors were used to detect both normal pressing and slip forces. [196] Ultrathin epidermal sensors patterned in a serpentine configuration were capable of sensing both temperature and strain (Figure 7e).…”