Robot

Linguistics

Process (computing)

Engineering

Philosophy

Strain gauge

Fabrication

Materials science

Stress (linguistics)

Bending

Operating system

Computer science

Shear stress

Acoustics

Physical chemistry

Strain (injury)

Mechanical engineering

Alternative medicine

Physics

Nanotechnology

Gauge factor

Internal medicine

Electrical resistance and conductance

Artificial intelligence

Composite material

Tactile sensor

Medicine

Chemistry

Electrode

Pressure sensor

Pathology

ACS Nano

Tactile sensors that can mechanically decouple, and therefore differentiate, various tactile inputs are highly important to properly mimic the sensing capabilities of human skin. Herein, we present an all-solution processable pressure insensitive strain sensor that utilizes the difference in structural change upon the application of pressure and tensile strain. Under the application of strain, microcracks occur within the multiwalled carbon nanotube (MWCNT) network, inducing a large change in resistance with gauge factor of ∼56 at 70% strain. On the other hand, under the application of pressure to as high as 140 kPa, negligible change in resistance is observed, which can be attributed to the pressure working primarily to close the pores, and hence minimally changing the MWCNT network conformation. Our sensor can easily be coated onto irregularly shaped three-dimensional objects (e.g., robotic hand) via spray coating, or be attached to human joints, to detect bending motion. Furthermore, our sensor can differentiate between shear stress and normal pressure, and the local strain can be spatially mapped without the use of patterned electrode array using electrical impedance tomography. These demonstrations make our sensor highly useful and important for the future development of high performance tactile sensors.

Pressure Insensitive Strain Sensor with Facile Solution-Based Process for Tactile Sensing Applications