Flexible Pressure Sensors Based on Molybdenum Disulfide/Hydroxyethyl Cellulose/Polyurethane Sponge for Motion Detection and Speech Recognition Using Machine Learning

Abstract

Flexible pressure sensors with excellent performance have broad application potential in wearable devices, motion monitoring, and human−computer interaction. In this paper, a flexible pressure sensor with a porous structure is proposed by coating molybdenum disulfide (MoS 2 ) and hydroxyethyl cellulose (HEC) on a polyurethane (PU) sponge skeleton. The obtained sensor has excellent sensitivity (0.746 kPa −1 ), a wide detection range (250 kPa), fast response (120 ms), and outstanding repeatability over 2000 cycles. It is proven that the sensor can realize human motion detection and distinguish the touch of varying strength. In addition, a pressure sensing array was fabricated to reflect the pressure distribution and recognize the writing of Arabic numerals. Finally, the sensor performs speech detection through throat muscle movements, and high-accuracy (97.14%) speech recognition for seven words was achieved by a machine learning algorithm based on the support vector machine (SVM). This work provides an opportunity to fabricate simple flexible pressure sensors with potential applications in next-generation electronic skin, health detection, and intelligent robotics.

Unraveling the Ion Uptake Capacitive Deionization of Sea- and Highly Saline-Water by Sulfur and Nitrogen Co-Doped Porous Carbon Modified with Molybdenum Sulfide

“…Observation of the strong vibrations at ∼977, ∼870, and ∼750 cm –1 related to the stretching modes of oxygen in the MoO, Mo–O, and Mo–O–Mo which can be attributed to the layered orthorhombic phase of α-MoO 3 . The tiny bands located at ∼1400 and ∼1397 cm –1 are ascribed to the stretching vibration of the S–H and S–Mo–S groups in the MoS 2 /S,N-pCs. , Besides, the absorption band located at ∼610–650 cm –1 can be assigned to the stretching vibration of Mo–S and C–S groups. , …”

“…45,46 Besides, the absorption band located at ∼610− 650 cm −1 can be assigned to the stretching vibration of Mo−S and C−S groups. 45,47 Raman spectroscopy was utilized for further characterization of the MoS 2 /S,N-pCs in comparison to MoO 3 /N-pCs, N-pCs, and N−Cs (Figure 3d). The observation of two characteristic peaks around 1350 and 1590 cm −1 , which are respectively assigned to the D and G bands, provides evidence of the successful synthesis of carbonaceous materials.…”

“…44 The tiny bands located at ∼1400 and ∼1397 cm −1 are ascribed to the stretching vibration of the S−H and S−Mo−S groups in the MoS 2 / S,N-pCs. 45,46 Besides, the absorption band located at ∼610− 650 cm −1 can be assigned to the stretching vibration of Mo−S and C−S groups. 45,47 Raman spectroscopy was utilized for further characterization of the MoS 2 /S,N-pCs in comparison to MoO 3 /N-pCs, N-pCs, and N−Cs (Figure 3d).…”

An ultrasensitive flexible pressure, temperature, and humidity sensor based on structurally adjustable nano-through-hole array films

“…These devices have obvious advantages such as high applicability, reliability, and comfort when applied to the human body. [4][5][6][7][8] However, integrating multiple stimulus signal responses, high sensitivity, and flexibility into a single sensor is still challenging. At present, only a few previous studies have involved a sensor that can detect multiple physical stimulus signals at the same time.…”

Conversion of Electronic Waste to an Electrochemical Sensor for Dopamine: Using MXene-Modified Liquid Crystal Display Panels

“…In order to overcome these demerits, a variety of nanomaterials can be used to modify the electrodes. Researchers have focused on two-dimensional (2D) materials owing to their adaptability to various synthesis techniques, substantial electrochemically active surface areas, good conductivity, and the ability to form extra routes for analyte interaction . MXenes, a class of transitional metal carbides/nitrides, have gained popularity due to their appealing characteristics such as electron transport behavior, excellent conductivity, biocompatibility, and the capacity to create freestanding films .…”