Haptically Quantifying Young's Modulus of Soft Materials Using a Self‐Locked Stretchable Strain Sensor

Abstract

and ii) dynamic, in which the amplitude, phase, and frequency of a sample are detected under vibration. [7] These principles inspired conventional bulky benchtop instruments, [8] which are time consuming and limited to well-cut samples with known sizes. Simple and rapid Young's modulus measurements of soft materials with miniaturized platforms are highly demand for improved efficiency and adaptability to new applications, including fast-paced scenarios requiring on-demand and in situ monitoring.Remarkable progress has been made for improved adaptability to new scenarios in the past decades. [9][10][11][12] The static principle has developed indentation methods using theories of contact mechanics such as the Hertz model, [13] which calculates the Young's modulus from force-displacement curves when an indenter presses a stabilized sample regardless of sample sizes. This superiority opens up microscale mechanical characterization such as atomic force microscopy and nanoindentation. [1,9,14,15] However, the force-displacement curves require force sensors, displacement feedback systems, and stabilized samples, limiting to benchtop measurements. Indentation methods also yielded pen-sized and hand-held instruments enabling in vivo study Simple and rapid Young's modulus measurements of soft materials adaptable to various scenarios are of general significance, and they require miniaturized measurement platforms with easy operation. Despite the advances made in portable and wearable approaches, acquiring and analyzing multiple or complicated signals necessitate tethered bulky components and careful preparation. Here, a new methodology based on a self-locked stretchable strain sensor to haptically quantify Young's modulus of soft materials (kPa-MPa) rapidly is reported. The method demonstrates a fingertip measurement platform, which endows a prosthetic finger with human-comparable haptic behaviors and skills on elasticity sensing without activity constraints. A universal strategy is offered toward ultraconvenient and high-efficient Young's modulus measurements with wide adaptability to various fields for unprecedented applications.

Artificial Sense Technology: Emulating and Extending Biological Senses

“…Finally, sensory visualization that is reliable and shareable becomes reality through the digitization of sensation. Cui et al developed a minimized fingertip modulus sensor (FMS), which can haptically quantify the Young’s modulus of soft materials . The FMS was used to monitor Young’s modulus variation of swollen tissues in patients who suffered from bone fractures, indicating suitable surgery dates that matched the decisions of an experienced doctor.…”

“…Cui et al developed a minimized fingertip modulus sensor (FMS), which can haptically quantify the Young's modulus of soft materials. 28 The FMS was used to monitor Young's modulus variation of swollen tissues in patients who suffered from bone fractures, indicating suitable surgery dates that matched the decisions of an experienced doctor. In addition to light, sound, chemical, and mechanical stimuli, a broad range of physical (e.g., electroencephalogram, electrocardiogram, and electromyogram) and chemical (e.g., volatile organic compounds, ions, and other metabolites) information exists that is closely related to humans but easily ignored by biological sensory systems.…”

Highly-integrated, miniaturized, stretchable electronic systems based on stacked multilayer network materials

“…Stretchable electronics represent an area of focusing interest in the past decade, in part owing to the broad spectrum of applications, spreading from health monitoring (1)(2)(3)(4)(5)(6)(7)(8) and disease treatment (9)(10)(11)(12)(13)(14)(15)(16), to internet of things (17)(18)(19)(20) and soft robots (21)(22)(23)(24)(25)(26)(27)(28), and to virtual reality and augmented reality (29)(30)(31)(32)(33)(34). Stretchable inorganic electronics mainly rely on integration of high-performance inorganic components with elastomer substrates, where ingenious structural designs are key to a high degree of stretchability of the device system, since inorganic electronic components are usually rigid and brittle (35)(36)(37)(38)(39)(40)(41)(42).…”

Stress-deconcentrated ultrasensitive strain sensor with hydrogen-bonding-tuned fracture resilience for robust biomechanical monitoring

“…Flexible strain sensors have drawn increasing attention for healthcare monitoring, daily activity tracking, and humanrobotics communication [1][2][3][4][5]. A myriad of strain sensors based on various sensing mechanisms including resistance [6], capacitance [7,8], piezoresistive [9], piezoelectric [10], and inductance [11,12] have been developed.…”