Wearable
integrated sensing devices with flexible electronic elements
exhibit enormous potential in human–machine interfaces (HMI),
but they have limitations such as complex structures, poor waterproofness,
and electromagnetic interference. Herein, inspired by the profile
of Lindernia nummularifolia (LN), a bionic stretchable optical strain
(BSOS) sensor composed of an LN-shaped optical fiber incorporated
with a stretchable substrate is developed for intelligent HMI. Such
a sensor enables large strain and bending angle measurements with
temperature self-compensation by the intensity difference of two fiber
Bragg gratings’ (FBGs’) center wavelength. Such configurations
enable an excellent tensile strain range of up to 80%, moreover, leading
to ultrasensitivity, durability (≥20,000 cycles), and waterproofness.
The sensor is also capable of measuring different human activities
and achieving HMI control, including immersive virtual reality, robot
remote interactive control, and personal hands-free communication.
Combined with the machine learning technique, gesture classification
can be achieved using muscle activity signals captured from the BSOS
sensor, which can be employed to obtain the motion intention of the
prosthetic. These merits effectively indicate its potential as a solution
for medical care HMI and show promise in smart medical and rehabilitation
medicine.