Western Blot analysis of collagen type II, aggrecan, and HSP70 expression in 3D chondrogenic pellet cultures using hMSCs from the 24 year old donor at Day 17 and Day 24.

<p>(A), (C), (E), (G), (I) and (K) are the images of Western blot membranes while (B), (D), (F), (H), (J) and (L) are their semi-quantified band intensities respectively (Chon: chondrogenic differentiated hMSCs, and chon+HS: chondrogenic differentiated hMSCs with heat shock).</p

Semi-quantified Immunohistochemical staining Intensity.

<p>Chon: Chondrogenic; HS: Heat Shock; Col: Collagen; n = 3 for average ratio.</p

Nanoscale Triboelectric-Effect-Enabled Energy Conversion for Sustainably Powering Portable Electronics

Harvesting energy from our living environment is an effective approach for sustainable, maintenance-free, and green power source for wireless, portable, or implanted electronics. Mechanical energy scavenging based on triboelectric effect has been proven to be simple, cost-effective, and robust. However, its output is still insufficient for sustainably driving electronic devices/systems. Here, we demonstrated a rationally designed arch-shaped triboelectric nanogenerator (TENG) by utilizing the contact electrification between a polymer thin film and a metal thin foil. The working mechanism of the TENG was studied by finite element simulation. The output voltage, current density, and energy volume density reached 230 V, 15.5 μA/cm², and 128 mW/cm³, respectively, and an energy conversion efficiency as high as 10–39% has been demonstrated. The TENG was systematically studied and demonstrated as a sustainable power source that can not only drive instantaneous operation of light-emitting diodes (LEDs) but also charge a lithium ion battery as a regulated power module for powering a wireless sensor system and a commercial cell phone, which is the first demonstration of the nanogenerator for driving personal mobile electronics, opening the chapter of impacting general people’s life by nanogenerators

Sulfated GAG (sGAG) content normalized to wet weight in 3D pellet culture on Day 10, 17 and 24, with and without HS (chon: chondrogenic differentiated hMSCs, and chon+HS: chondrogenic differentiated hMSCs with heat shock).

<p>Data represent the mean ± SD (n = 4). P values were calculated using student t-test.</p

Representative images of immunohistochemical staining of inducible heat shock protein 70 (HSP70) in pellet culture samples on (A) Day 17 (B) Day 24.

<p>Scale bar: 25 μm. (chon: chondrogenic differentiated hMSCs, and chon+HS: chondrogenic differentiated hMSCs with heat shock).</p

Characterization of hMSCs by flow cytometric analysis.

<p>(<b>A</b>) Isolated hMSCs were positive for surface markers CD146, CD29, CD147 and CD44, and negative for CD45 and CD34. (<b>B</b>) The individual percentages of each surface marker expressed in these cells from the quantitative FACS analysis. Data represent the mean ± SD (n = 3).</p

Nanoscale Triboelectric-Effect-Enabled Energy Conversion for Sustainably Powering Portable Electronics

Harvesting energy from our living environment is an effective approach for sustainable, maintenance-free, and green power source for wireless, portable, or implanted electronics. Mechanical energy scavenging based on triboelectric effect has been proven to be simple, cost-effective, and robust. However, its output is still insufficient for sustainably driving electronic devices/systems. Here, we demonstrated a rationally designed arch-shaped triboelectric nanogenerator (TENG) by utilizing the contact electrification between a polymer thin film and a metal thin foil. The working mechanism of the TENG was studied by finite element simulation. The output voltage, current density, and energy volume density reached 230 V, 15.5 μA/cm², and 128 mW/cm³, respectively, and an energy conversion efficiency as high as 10–39% has been demonstrated. The TENG was systematically studied and demonstrated as a sustainable power source that can not only drive instantaneous operation of light-emitting diodes (LEDs) but also charge a lithium ion battery as a regulated power module for powering a wireless sensor system and a commercial cell phone, which is the first demonstration of the nanogenerator for driving personal mobile electronics, opening the chapter of impacting general people’s life by nanogenerators

Nanoscale Triboelectric-Effect-Enabled Energy Conversion for Sustainably Powering Portable Electronics

Harvesting energy from our living environment is an effective approach for sustainable, maintenance-free, and green power source for wireless, portable, or implanted electronics. Mechanical energy scavenging based on triboelectric effect has been proven to be simple, cost-effective, and robust. However, its output is still insufficient for sustainably driving electronic devices/systems. Here, we demonstrated a rationally designed arch-shaped triboelectric nanogenerator (TENG) by utilizing the contact electrification between a polymer thin film and a metal thin foil. The working mechanism of the TENG was studied by finite element simulation. The output voltage, current density, and energy volume density reached 230 V, 15.5 μA/cm², and 128 mW/cm³, respectively, and an energy conversion efficiency as high as 10–39% has been demonstrated. The TENG was systematically studied and demonstrated as a sustainable power source that can not only drive instantaneous operation of light-emitting diodes (LEDs) but also charge a lithium ion battery as a regulated power module for powering a wireless sensor system and a commercial cell phone, which is the first demonstration of the nanogenerator for driving personal mobile electronics, opening the chapter of impacting general people’s life by nanogenerators

Representative images of immunohistochemical staining of aggrecan in pellet culture samples on (A) Day 17 (B) Day 24.

<p>Scale bar: 25 μm. (chon: chondrogenic differentiated hMSCs, and chon+HS: chondrogenic differentiated hMSCs with heat shock).</p

Pyroelectric Nanogenerators for Driving Wireless Sensors

We demonstrate a pyroelectric nanogenerator (PENG) based on a lead zirconate titanate (PZT) film, which has a pyroelectric coefficient of about −80 nC/cm²K. For a temperature change of 45 K at a rate of 0.2 K/s, the output open-circuit voltage and short-circuit current density of the PENG reached 22 V and 171 nA/cm², respectively, corresponding to a maximum power density of 0.215 mW/cm³. A detailed theory was developed for understanding the high output voltage of PENG. A single electrical output pulse can directly drive a liquid crystal display (LCD) for longer than 60 s. A Li-ion battery was charged by the PENG at different working frequencies, which was used to drive a green light-emitting diode (LED). The demonstrated PENG shows potential applications in wireless sensors