Micro-machines can be constructed with help of single-particle engine: JNCASR Study

A micrometre-sized Stirling engine was created by a team of researchers from the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute of the Department of Science & Technology of the Government of India, and the Indian Institute of Science (IISc) Bangalore. This is a type of heat engine that converts thermal energy into kinetic energy by heating and cooling the working gas sealed in the storage tank.

According to a study by researchers that tested the reaction of such micro engines to noise changes in the surrounding medium, the performance of tiny engines containing single colloidal particles varies with modulations in environmental noise. This knowledge will be critical in the development of micromachines that function in complicated biological settings, which are becoming increasingly significant in biomedical engineering.

Micro-machines can be constructed with help of single-particle engine: study by JNCASR

Micromechanical machines are at the cutting edge of modern science and technology, with uses spanning from aerospace to biomedical engineering. Scientists have recently experimented with building such machines out of single colloidal particles. Mechanical work and power generation are heavily influenced by environmental changes in these systems. As a result, comprehending the impact of environmental noise statistics on energy conversion is critical to comprehending the operation of micro-machines like naturally occurring molecular motors that carry out transportation within a live cell.

They discovered that the engine responds to non-thermal noise in the presence of reservoirs (the fluid that holds the colloidal particle) with thermal noise (due to the random motion of the water molecules) and thermal noise (noise from sources other than temperature, such as fluctuating laser beams). This research was recently published in the journal ‘Nature Communications.'

The study states, “Colloidal heat engines are paradigmatic models to understand the conversion of heat into work in a noisy environment - a domain where biological and synthetic nano/micro machines function. While the operation of these engines across thermal baths is well-understood, how they function across baths with noise statistics that is non-Gaussian and also lacks memory, the simplest departure from the thermal case, remains unclear. Here we quantified the performance of a colloidal Stirling engine operating between an engineered memoryless non-Gaussian bath and a Gaussian one. “

Reservoir engineering technique used in the study 

The JNCASR team achieved this with the use of a new reservoir engineering technique that uses laser traps to impart fake noise to colloidal particles, allowing for a wide range of artificial noise that was previously impossible to achieve. The researchers also demonstrated that the mode of maximum power production may be achieved at varying cycle speeds (the time it takes for one Stirling cycle to complete) without impacting the engine's efficiency.

The methods used for the study were:

• Experimental set-up for reservoir engineering
• Image acquisition and processing
• Non-Gaussian Reservoir Engineering

Insights from the study to be useful for biomedical engineering 

The rate of broadening of the laser and the relaxation rate of particle vibration determine work, power, and efficiency, or the engine's performance. This relaxation rate can be varied by modifying the external noise/fluctuation data, and therefore the engine's performance can be altered. In the presence of non-thermal (no heat or change in temperature) noise, molecular motors that carry out transportation inside a live cell function far from equilibrium (take only forward steps). As a result, comprehending the role of non-thermal noise in non-equilibrium energy conversion will provide valuable insight into the design of any artificial micro-machine that operates in complicated biological contexts.

(IMAGE: SHUTTERSTOCK)