Development of Diamond like Carbon based IR Optics on Germanium
DLC is known to have good IR transmission properties and is currently a favourable choice of IR optics used in harsh environmental conditions. A single layer of DLC coating on either side of a germanium wafer was synthesised and peak transmission was for a wavelength of 2.4 µm was observed to be 96% and for 3-5 µm range, a peak transmission of 96% was observed. The coatings have passed a few tests that were conducted as per MIL-C-48497A standards.This coating has been indigenised for IR transmission. This has been funded by Department of Science and Technology.

Development of High Hardness Diamond Like Carbon thin films at room temperature

A DLC synthesis process was developed at room temperature using a Roth & Rau RF PECVD with hardness of DLC of about 32.7 GPa using an Agilent G200 Nano Indentor. TEM images (from an FEI Titan G2 60-300) indicated an amorphous – crystalline matrix. The films were also characterised using Raman Spectroscopy (Seki Tecnotron) to evaluate sp³ hybridisation.

Implementation of Diamond Like Carbon on various materials like Silicon, Stainless Steel, Carbon Steel, High Speed Steel, Carbide tools, PMMA, Soda Lime Glass, Ti-Al-V alloy and Aluminium alloys.

An investigation into the mechanism of DLC adhesion on various substrates was undertaken. The adhesion of DLC was studied without the use of any buffer layer in most cases by plasma treatment using various gases.

A Veeco Dimension V AFM was used to study to the plasma treated surfaces. This lead to self cleaning surfaces, required on various applications that needs scratch protection and low wettability. A part of this work has been implemented in an Department of Science & Technology project.

Development of Carbon Nanotubes for super black applications

A feasibility study on synthesis of CNTs on various substrates like Stainless Steel, Silicon, Anodised Aluminium, Anodised Titanium, Titanium was undertaken. Different strategies to achieve a film growth of CNT was employed which included, usage of catalyst layers and optimising the thickness of each of the layer, varying gas ratios of different hydrocarbon gases etc. This is required for components to absorb all light in space. This project was funded by Indian Space Research Organisation.

Proof of Concept Demonstrations

1. Development of UV Sensor head using thin film synthesised carbon nanotubes for monitoring aero engine combustion. The sensor has almost zero hysteresis.

2. Development of thin film micro-heater

3. Development of flexible temperature sensor using thin films on transparent cellulose acetate sheet for aerospace components

4. Development of alternate thin film materials for UV mask plates for MEMS devices.

5. Protective thin film coatings for watch casings. Diamond Like Carbon coated on watch case

6. Development of CNT-Ceramic/Metal 2D nanomaterial for mechanical and thermal applications

Development of Metrology Artefacts:

a.High precision optical standard glass scales:

CMTI has developed high precision optical standard glass scales by using state of the art facility available in the Institute. These artefacts are used for the measurement, inspection, calibration and positioning in Imaging Equipments, Microscopy, Scanning etc. The Grating straightness & pitch accuracy of the developed artefacts is within 1 µm.

b. High precision optical standard calibration masks:

CMTI has developed the high precision optical standard calibration masks for the calibration of Microscopy equipments. A low-reflectivity chrome coating of 100 nm thick was vacuum sputtered on soda lime glass of 1.5 mm thick using in-house physical vapor deposition(PVD) system. Then using KrF- 248 nm laser, the features from 10 µm to 1.5 mm were etched out in the mask without affecting the base substrate.

c. Development of depth master

CMTI has taken an initiative for the indigenous development of metrology artefacts for the Indian industries. We have developed a depth master of width 150 µm and depth of 10 µm in glass using Femtosecond laser micromachining system.

d. Glass gratings for Micro-analyser

By using Femtosecond laser micromachining system four angular gratings were created on glass at four different angles namely 0°, 1°, 3° and 5°. Each grating is having a dimension of 0.2 x 2 mm.

Technology developments in Micro-machining area:

i.Development of technology for marking jewellery Diamonds

Successfully established a process for marking diamonds using ultrafast pulsed laser micromachining system for one of the country’s leading Jewellery maker. The size of the diamond is 1.2 mm where as the marking dimension is 50×100 µm.

ii. Development of Micro-fluidic devices

A microfluidic device was fabricated in glass using femtosecond laser micromachining system having an array of 25×10 of micro holes with Ø 10 µm and depth of 5 µm.

CMTI has also developed a micro-fluidic device for bio-medical application using ultra fast pulsed laser to one of the Indian start-up company. The micro-fluidic channel cross section is around 50 microns and the channel is done on borosilicate glass.

iii. Development of technology for the synthesis of high purity Copper nano particles using ultra fast pulsed laser.

CMTI has successfully established a process to synthesize high purity copper nanoparticles of size 40 – 50 nm.

iv.Development of micro-needles for bio-medical applications

CMTI has developed square and circular micro-needles  on Stainless steel and PMMA materials for drug delivery applications.

We offer the utilisation of our laboratory services for both deposition using PVD and CVD along with micromachining using lasers. The facilities list consists of all the specifications of the equipment that are available for services.

Specific services include but not limited to the deposition of Diamond Like Carbon, Carbon Nanotubes, Thin film micromachining, Micro fluidic device, sensor micromachining using Excimer and Femto second laser. Please contact us if you have any queries for customised solutions.

*The rates of the services shall be changed periodically. Please contact us for exact prices. Cost of the equipment is based on the usage on a per hourly basis. 18% GST Extra.

Technologies Developed

1. Synthesis of Room Temperature Diamond Like Carbon on any surface with high hardness >2500 HV
2. MIL – C Standard qualified DLC films for Infra Red Windows for Anti Reflection and Night Vision Application
3. Diamond Like Carbon for functional and aesthetic surfaces
4. Carbon Nanotube direct deposition on aerospace materials
5. Super Black Carbon Nanotubes for space applications

Technologies & Products Developed

1. Development of high precision optical standard glass scales
2. High precision optical calibration masks
3. Synthesis of high purity copper nano-particles
4. Micro-needles for drug delivery applications
5. Micro-fluidic channels for Bio-medical applications

Patent filed:

• “System and Method for making micro needles using microstereo lithography”

Indian Patent Office Application No.: 660/CHE/2015 dated 11.2.15

List of Relevant Publications

• AshishVarade, Ankit. K, Niranjan Reddy, M. Chellamalai, N. Balashanmugam, P.V. Shashikumar, “Diamond-like carbon coating made by RF Plasma enhanced chemical vapour deposition for protective antireflective coatings on germanium”, Procedia Material Science, vol. 5, 2014, pp. 1015-1019
• Ankit. K, K. Niranjan Reddy, AshishVarade, M. Chellamalai, N. Balshanmugam, P.V. Shashikumar, “Development of hard DLC coatings at Room Temperature using RF PECVD process”, Presented at International Colloquium on Material, Manufacturing and Metrology, 2014, IIT Madras, Chennai.
• K. Niranjan Reddy, AshishVarade, Ankit. K,  J. Joshua, D. Sasen, M. Chellamalai, P.V. Shashikumar, “Double side coating of DLC on silicon by RF-PECVD for AR application”, Procedia Engineering, vol. 97, 2014, pp. 1416-1421.
• AshishVarade,  K. Niranjan Reddy, D. Sasen, Ankit. K, M. Chellamalai, P.V. Shashikumar, “Detailed Raman Study of DLC coating on Si (100) made by RF-PECVD”, Procedia Engineering, vol. 97, 2014, pp. 1452-1456.
• Sunil, M, Ankit. K, K. Niranjan Reddy, M. Chellamalai, N. Balashanmugam, “Experimental Investigation of RF Sputtered SiO₂ Thin films for evaluation of uniformity” presented at Advances in Metrology, 2016, National Physical Laboratory, New Delhi
• Ankit. K,  AshishVarade, SarmisthaDhan, K. Niranjan Reddy, M. Chellamalai, N. Balashanmugam, “Synthesis of high hardness, low COF diamond-like carbon using RF-PECVD at room temperature and evaluating its structure using electron microscopy”, Diamond and Related Materials, vol. 78, 2017, pp. 39-43.
• Ankit. K,  AshishVarade, SarmisthaDhan, K. Niranjan Reddy, M. Chellamalai, N. Balashanmugam, “Synthesis of high hardness IR optical coating using diamond-like carbon by PECVD at room temperature”, Diamond and Related Materials, vol.80, 2017, pp. 108-112
• Ankit. K, K. Niranjan Reddy, M. Chellamalai, N. Balashanmugam, “Feasibility of CNT based Sensor for UV Detection in Combustion Process for Aerospace Applications” Proceedings of 10^th International Conference on Precision, Meso, Micro and Nano Engineering (COPEN-2017), 2017, IIT Madras, pp. 353-356.
• Ankit. K, K. Niranjan Reddy, AshishVarade, SarmisthaDhan, M. Chellamalai, N. Balashanmugam, “Development of Implementable Diamond-like Carbon Coating for Improving Scratch, Wear and Optical Properties for Practical Industrial Applications”, Proceedings of 10^th International Conference on Precision, Meso, Micro and Nano Engineering (COPEN-2017), 2017, IIT Madras, pp. 372-375.
• Ankit.K, Sunil. M, K. Niranjan Reddy, N. Balashanmugam, “Development of Nanometre Edge Resolution Metrology Standards for Video Measuring Systems” Proceedings -Abstract at Advances in Metrology, 2019, National Physical Laboratory, New Delhi
• Sunil. M, Ankit.K, K. Niranjan Reddy, N. Balashanmugam “Process for the Development of high precision gratings/scales” selected at Advances in Metrology, 2019, Proceedings -Abstract at Advances in Metrology, 2019, National Physical Laboratory, New Delhi
• Ankit. K, K. Niranjan Reddy, Gokul, N. Balashanmugam, “Investigation on the effect of nucleation time on CNT growth using RF-PECVD” – Manufacturing Technology Today, Vol. 18 (3), Mar 2019.