Sunday, June 21, 2020

Leidenfrost effect

Leidenfrost effect

It is a physical phenomenon, where the volatile liquid drops are in levitation upon close contact with the hot surface. The hotness of the surface is significantly higher than the boiling point of the liquid. An insulating vapor layer is developed by the liquid on the deposited surface which inhibits the drops to evaporate and the generated repulsive force propels the random movement of the liquid drop. It was first proposed by J. G. Leidenfrost.

Features:

A lifetime in the order of minute scale
self-propelled
Absence of friction
Rich dynamics
Glides at a slight inclination
Drop deformation

Inverse Leidenfrost effect

An inverse Leidenfrost effect is observed when the ambient temperature liquid drops are deposited on liquid nitrogen, which maintains a cryogenic environment as the boiling temperature of liquid nitrogen is -196 °C. The rate of evaporation of liquid nitrogen is so fast that any liquid at ambient temperature approaches to nitrogen bath levitates the drops instantly.

Features:

The time scale in the tens of minutes
Self-propelled
Absence of friction
Counterintuitive dynamics
Gliding in straight lines
Drop sinking

Application: Biological materials (Cells, Proteins) transportation in the biomedical field.

pnas.org/content/116/4/1174

Monday, June 15, 2020

IoT: A Parallel Platform to Advance Drug Delivery

IoT:

Internet of things (IoT) is a cutting edge device through which data collection, manipulation, and action are being taken. IoT helps in improving drug efficacy, detecting errors, the limit of detection, regulatory compliance, improving R&D productivity, reducing the manpower, and effective cost.

Organ-on a chip and chip-in a pill is the recent advancement of this technology.

Organ-on a chip:

It is a polymer which contains microfluidic channels lined by living cells. These administrated microchip helps to understand the regulatory functions of living human organs including lung, brain, kidney, skin, spleen, liver, heart, gut, bone, etc. Organ-on a chip plays a key role to accelerate the development of a new drug for which the systematic treatment is paradoxical. It helps to improve development and productivity, reducing data processing, reporting, and analysis time.

Cons:

* Surface effects dominate over volume effect.

* Little mixing during laminar flow.

* Not portable.

Chip-in a pill:

It is an ingestible pill used for in-vivo imaging to understand the inner functions and drug effects on it. these pills transmit the data to a wearable device then it probed by healthcare exports for disease diagnosis. This procedure also helps to improve drug efficacy with reduced time and provides a platform to understand the problem more profoundly.