Highly sensitive, wide-pressure and low-frequency characterized pressure sensor based on piezoresistive-piezoelectric coupling effects in porous wood

Versatile Mesoporous All-Wood Sponge Enabled by In Situ Fibrillation toward Indoor–Outdoor Energy Management and Conversion

“…We presumably attributed the improved piezoelectric outputs to the following reasons: (1) in situ fibrillation remarkably enhanced the compressibility of wood, thus enabling the ready displacement of crystalline cellulose in wood cell walls under external stress; (2) the introduction of carboxyl groups on lignocellulosic components was conducive to an increased in the charge polarization capacity of wood; (3) the highly mesoporous and heterogeneous structure would contribute the charge separation during the deformation of in situ fibrillated wood . Additionally, the piezoelectric output of in situ fibrillated wood was superior to that of most reported all-wood materials such as fungi-treated wood (15 × 15 × 13.2 mm 3 ) with an output voltage of 0.87 V under a periodical pressure of 45 kPa at ∼3.3 Hz, acidic H 2 O 2 delignified wood (15 × 15 × 14 mm 3 ) with an output voltage of 0.69 V under a periodical pressure of 22 kPa at ∼1.1 Hz, and NaOH-Na 2 SO 3 delignified wood (10 × 10 × 10 mm 3 ) with an output voltage of 0.65 V under a periodical pressure of 35 kPa at 0.6 Hz . A combination of high compressibility and piezoelectricity makes the in situ fibrillated wood highly applicable for a wide range of mechanoelectrical power conversion systems, e.g., mechanical energy-powered LED lighting (Figure S6).…”

“…53 Additionally, the piezoelectric output of in situ fibrillated wood was superior to that of most reported allwood materials such as fungi-treated wood (15 × 15 × 13.2 mm 3 ) with an output voltage of 0.87 V under a periodical pressure of 45 kPa at ∼3.3 Hz, 54 acidic H 2 O 2 delignified wood (15 × 15 × 14 mm 3 ) with an output voltage of 0.69 V under a periodical pressure of 22 kPa at ∼1.1 Hz, 55 and NaOH-Na 2 SO 3 delignified wood (10 × 10 × 10 mm 3 ) with an output voltage of 0.65 V under a periodical pressure of 35 kPa at 0.6 Hz. 11 A combination of high compressibility and piezoelectricity makes the in situ fibrillated wood highly applicable for a wide range of mechanoelectrical power conversion systems, e.g., mechanical energy-powered LED lighting (Figure S6). Furthermore, a long-term cyclic compression/releasing test was conducted to confirm the durability of in situ fibrillated wood as a sustainable piezoelectric nanogenerator.…”

“…The microstructure of wood can be modified on-demand by using various chemical/biological/mechanical approaches, − enabling wood to be a versatile platform for advanced building applications. In the past decade, increasing research has focused on the exploitation of high-strength wood with intriguing light/thermal/sound management, − sensing, and energy-conversion properties, significantly boosting the applicability of wood in next-generation green buildings.…”

An ultra-soft conductive elastomer for multifunctional tactile sensors with high range and sensitivity

“…3–5 As a result of their diverse range of applications, including electronic skin, 6 human–machine interaction, 7 and robotic arms, 8 extensive research has been devoted to the field of flexible tactile sensors. These sensors can be classified into four categories based on their principles: resistive, 9 capacitive, 10 piezoelectric, 11 and triboelectric. 12,13…”

Flexible Sensors with a Multilayer Interlaced Tunnel Architecture for Distinguishing Different Strains

“…Sensors that respond to stretch or compression strains are typically attached to human skin to detect strains caused by joint motions and output corresponding response signals (e.g., resistance, voltage, capacitance). Currently, a variety of flexible strain sensors have been developed, such as microcrack sensors for highly sensitive sensing of small strains, self-powered triboelectric nanogenerators, etc., for the monitoring of body joints, facial expressions, pulses, etc. − It is important to note that the motion of the joints causes complex deformations in the flexible sensors; for example, flexion of the finger joints causes the sensors to undergo compressive, stretching, and bending deformations. However, most flexible sensors tend to output the response signal with the same trend for different strain stimuli, − making it difficult to provide realistic feedback on joint motion.…”