Contact-Free Online Monitoring of Bioreactor Cell Cultures with Magnetic Resonance Relaxometry.

Frequent, low-latency measurements of bioreactor culture growth are critical for achieving maximum culture efficiency and productivity. Typical cell density and viability measurements are made by manually removing a sample from the culture, but this approach is both slow and unsuitable for small culture volumes, which cannot support frequent destructive sampling. In this work, automated magnetic resonance relaxometry measurements of a sealed bioreactor system are used to estimate the cell density and provide qualitative information about the culture in near real-time.

Wind dispersal of battery-free wireless devices.

Plants cover a large fraction of the Earth's land mass despite most species having limited to no mobility. To transport their propagules, many plants have evolved mechanisms to disperse their seeds using the wind. A dandelion seed, for example, has a bristly filament structure that decreases its terminal velocity and helps orient the seed as it wafts to the ground.