WO2013008072A2

WO2013008072A2 - A process for preparing polymer composition of functionalized epoxy resist, polymer composition and applications thereof

Info

Publication number: WO2013008072A2
Application number: PCT/IB2012/001328
Authority: WO
Inventors: Anil Kumar
Original assignee: Indian Institute Of Technology, Bombay
Priority date: 2011-07-08
Filing date: 2012-07-06
Publication date: 2013-01-17
Also published as: WO2013008072A3

Abstract

The present disclosure relates to a process for preparation of a polymer composition comprising: blending an epoxy resist, preferably SU-8, and at least one compound of formula (I) to obtain a reaction mixture; and curing the reaction mixture to obtain the polymer composition. The present disclosure also relates to a polymer composition comprising a reaction product of an epoxy resist, preferably SU-8, and at least one compound of formula (I). The present disclosure further relates to a process for manufacturing a device comprising: fabricating a device with polymer composition comprising a reaction product of an epoxy resist, preferably SU-8; and at least one compound of formula (I) to obtain the fabricated device. The present disclosure also relates to a device comprising: a polymer composition comprising a reaction product of an epoxy resist, preferably SU-8; and at least one compound of formula (I).

Description

A PROCESS FOR PREPARING POLYMER COMPOSITION OF FUNCTIONALIZED EPOXY RESIST, POLYMER COMPOSITION AND APPLICATIONS THEREOF TECHNICAL FIELD

The present disclosure relates to a process for preparing a polymer composition comprising functionalized epoxy resist. The process of the present disclosure allows further functionalization of the polymer composition.

The present disclosure also relates to a polymer composition comprising functionalized epoxy resist and a device comprising the same. The present disclosure further relates to the process for manufacturing a device comprising the polymer composition.

The process of the present disclosure allows the formation of various patterns using the functionalized epoxy . based resist composition and selective functionalization after the device fabrication.

BACKGROUND

Epoxy based resists are widely used as structural elements in MEMS NEMS, microfluidic components, waveguides etc. and has received wide spread acceptance. An epoxy based photoresist after photo crosslinking exhibits excellent properties like mechanical strength, compatibility with biomaterials and chemical resistance. Surface properties of these resists have to be tailored for different applications and there are several methods to modify the surface of epoxy based resists. A number of methods have been employed, including adsorption of biomolecules, surface coating, plasma treatment, graft polymerization and chemical modification.

In "Simple Photografting Method to Chemically Modify and Micropattern the Surface of SU-8 Photoresist" (Langmuir 22, 2719-2725 (2006)), Wang et. al. reported UV mediated grafting of poly(acrylic acid) and other water soluble monomers to modify the surface of SU-8. In "Immobilization of DNA to polymerized SU-8 photoresist" (Biosensors and Bioelectronics 21 , 1327-1332 (2006)), Marie et. al. reported the immobilization of DNA to polymerized SU-8 surface. In "A novel dry method for surface modification of SU-8 for immobilization of biomolecules in Bio- MEMS" (Biosensors and Bioelectronics 22, 2429-2435 (2007)), Joshi et. al. reported a dry method for the surface modification of SU-8. They used the technique of Hot Wire CVD for pyrolytic dissociation of ammonia and grafting amine groups on to the surface. In "Off-wafer fabrication and surface modification of asymmetric 3D SU-8 microparticles", Tao et. al. did the surface modification of SU-8 microparticles. They treat SU-8 with H₂S0₄ and then following the traditional silane chemistry the surface groups of SU-8 was modified. In "Surface Modification of SU-8 for Enhanced

Biofunctionality and Nonfouling Properties" (Langmuir 24, 2631 -2636 (2008)), Tao et. al. modified SU- 8 surface for enhanced biofunctionality and nonfouling properties. Hydroxyl groups on the surface were created by treating with H₂S0₄.

So far there is no process available in the art which can allow the fabrication or modification of the device made up of epoxy based resists, specifically SU-8, after the formation of the device or casting of the polymer into any required structure.

From the above discussion it is clear that chemical functionalization of epoxy based resists, specifically SU-8, is an important area of research both from academic as well as commercial point of view. It would be ideal if a solution could be provided which allow a simple process for the functionalization which is compatible with the CMOS fabrication processes. Furthermore, if the functionalization protocol can be tuned to selectively functionalize domains in specific areas of the device either before or after the fabrication of the devices, then it will highly advantageous. SUMMARY

The present disclosure relates to a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture to obtain the polymer composition.

I

wherein X is selected from Ci-C₃₀ linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; where C1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, -Si(OMe)₃, - Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

The present disclosure also relates to a polymer composition comprising: a reaction product of SU-8 and at least one compound of formula I

The present invention further relates to a process for manufacturing a device comprising: fabricating a device with polymer composition comprising a reaction product of SU-8 and at least one compound of formula I to obtain the fabricated device.

The present invention also relates to a device comprising: a polymer composition comprising a reaction product of SU-8 and at least one compound of formula I.

These and other features, aspects, and advantages of the present subject matter will become better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

BRIEF DESCRIPTION OF DRAWINGS

The above and other features, aspects, and advantages of the subject- matter will become better understood with regard to the following description, appended claims, and accompanying drawings where:

Figure 1 shows the process flow for preparing heterogeneous ly functionalized

Cantilever in accordance with the process of the present disclosure.

Figure 2 shows the process flow for preparing various surfaces patterning of Thin Films in accordance with the process of the present disclosure.

Figure 3 shows the different patterns that can be obtained by the process of the present disclosure. ·

DETAILED DESCRIPTION

The present disclosure provides a process for preparation of a polymer composition comprising: blending an epoxy resist and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture to obtain the polymer composition;

wherein X is selected from C1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C 1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)3, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

An embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture to obtain the polymer composition;

where C i -C₃o linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture by heating the reaction mixture at a temperature in the range of 30 deg C to 300 deg C to obtain the polymer composition;

wherein X is selected from Ci -C₃₀ linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C | -C₃₀ linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Further, an embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 200 nm to 800 nm to obtain the polymer composition;

I

where Ci -C₃₀ linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups. Yet, another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula 1 to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 254 nm to 360 nm to obtain the polymer composition;

where C 1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)3, - Si(OMe)3, -Si(OPr)3, thiols, amides, propargyl or azide functional groups.

Still an embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 200 nm to 800 nm and by heating the reaction mixture at a temperature in the range of 30 deg C to 300 deg C the to obtain the polymer composition;

Another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture for a time period in the range of 1 min to 48 hours to obtain the polymer composition;

I

wherein X is selected from C 1-C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where Ci -C₃o linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Further, an embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and curing the reaction mixture for a time period in the range of 2 to 48 hours to obtain the polymer composition;

I

where Ci -C₃₀ linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

An embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8, at least one compound of formula I and an organic solvent to obtain a reaction mixture; and curing the reaction mixture to obtain the polymer composition;

wherein X is selected from Ci-C₃₀ linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where Cj-C₃o linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Another embodiment of the present disclosure, provides a process for preparation of a polymer composition comprising: blending SU-8, at least one compound of formula I and an organic solvent to obtain a reaction mixture; and curing the reaction mixture by heating the reaction mixture at a temperature in the range of 30 deg C to 300 deg C to obtain the polymer composition;

I

wherein X is selected from Ci-C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; where C I -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Further, an embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8, at least one compound of formula I and an organic solvent to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 200 nm to 800 nm to obtain the polymer composition;

I

wherein X is selected from Ci -C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

Yet, another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: SU-8, at least one compound of formula I and an organic solvent to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 254 nm to 360 nm to obtain the polymer composition;

I wherein X is selected from C 1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

Still an embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: SU-8, at least one compound of formula 1 and an organic solvent to obtain a reaction mixture; and curing the reaction mixture by photolytic treatment of the reaction mixture by a light having wavelength in the range of 200 nm to 800 nm and by heating the reaction mixture at a temperature in the range of 30 deg C to 300 deg C the to obtain the polymer composition;

I

wherein X is selected from Ci-C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C1-C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Still another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8, at least one compound of formula I, and an organic solvent to obtain a reaction mixture; and curing the reaction mixture for a time period in the range of 1 min to 48 hours to obtain the polymer composition;

I

wherein X is selected from C 1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C 1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Yet another embodiment of the present disclosure provides a process for preparation of a polymer composition comprising: blending SU-8, at least one compound of formula I, and an organic solvent to obtain a reaction mixture; and curing the reaction mixture for a time period in the range of 2 to 10 hours to obtain the polymer composition;

I

where C] -C₃o linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups. The organic solvent used in the process of the present disclosure is selected from gamma-butyrolactone, cyclopentanone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, ethyl lactate, diacetone alcohol, isopropyl alcohol, toluene, benzene, xylene, ethanol, methanol, acetone, ethyl acetate, chloroform, carbon tetrachloride, dichloromethane, D F, DMSO, preferably gamma- butyrolactone.

The whole process for preparing the polymer composition of the present disclosure is carried out under inert atmosphere, preferably under argon or nitrogen atmosphere.

The present disclosure also provides a polymer composition comprising: a reaction product of an epoxy resist and at least one compound of formula I;

I

wherein X is selected from C₁ -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

The epoxy resist used in the present disclosure is a resist having an epoxy ring branched with an alkyl or aryl functional group. The non-limiting example of epoxy resist in accordance with the present disclosure is SU-8.

An embodiment of the present disclosure provides a polymer composition comprising: a reaction product of SU-8 and at least one compound of formula I;

I wherein X is selected from C₁ -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C₁ -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)3, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Another embodiment of the present disclosure provides a polymer composition comprising a reaction product of SU-8 and at least one compound of formula I; and optionally comprising an ingredient selected from a group consisting of a solvent, a polymerization initiator, a surfactant, a filler and a binder or combination thereof. The solvent used in the polymer composition of the present disclosure is an organic solvent. The non-limiting examples of the solvent in accordance with the present disclosure are ethyl methyl ketone, diisopropyl ether, ethyl acetate, acetone, isopropyl alcohol, toluene, benzene, xylene, hexanes, pentane, methanol, Dimethylformamide (DMF), Dimethyl sulfoxide (DMSO) Hexamethylphosphoramide (HMPA), ethanol or butanol. The surfactant used in the present disclosure is selected from anionic surfactant, cationic surfactant and non-ionic surfactant. The surfactants generally used in the present disclosure are detergents having a hydrocarbon chain attached to a polar head group like acid, sodium salt of acid, sulphate, sodium salt of sulphate, and sodium salts. The polymerization initiators used in the polymer composition of the present disclosure are free radical initiators, metal catalyst based initiators, transition metal containing catalysts and lanthanides series based catalysts. The non-limiting examples of the polymer initiators in accordance with the present disclosure are Azobisisobutyronitrile (AIBN), organic peroxides and compounds. The fillers used in the polymer composition of the present disclosure are selected from, but not limited to, silica, calcium carbonate, magnesium carbonate, alumina, clay, magnesia or talc.

The polymer composition of the present disclosure is useful as a resist for microelectronics industry, and lab-on-a-chip industry. It can be used in the fabrication/manufacturing of functional microfluidics, functional cantilevers, functional waveguides, functional microelectromechanical systems (MEMS), functional nanoelectromechanical systems (NEMS) and functional bio-MEMS systems.

The present disclosure further provides a process for manufacturing a device comprising: fabricating a device with polymer composition comprising a reaction product of SU-8 and at least one compound of formula I to obtain the fabricated device;

I

wherein X is selected from C1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; and

where C 1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, -

Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

An embodiment of the present disclosure provides a process for manufacturing a device comprising: coating a device with polymer composition comprising a reaction product of SU-8 and at least one compound of formula I to obtain the fabricated device;

I

wherein X is selected from C 1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; and

Yet another embodiment of the present disclosure provides a process for manufacturing a device comprising: making a device with polymer composition comprising a reaction product of SU-8 and at least one compound of formula I to obtain the fabricated device:

I

wherein X is selected from Ci -C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; and

where C1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, -

Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

The non-limiting examples of the device which can be manufactured by the process of the present disclosure is selected from a micro electromechanical system (MEMS), bio-MEMS systems, nano electromechanical systems (NEMS), microfluidic, cantilevers, waveguides or semiconductor devices.

The present disclosure provides a device comprising: a polymer composition comprising a reaction product of SU-8 and at least one compound of formula 1;

I

wherein X is selected from Ci -C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, , ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; where Q-C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

An embodiment of the present disclosure provides a device made up of the polymer composition comprising a reaction product of SU-8 and at least one compound of formula I;

I

wherein X is selected from Q-C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, , ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C ₁ -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)₃, - Si(OMe)₃, -Si(OPr)₃, thiols, amides, propargyl or azide functional groups.

Yet another embodiment of the present disclosure provides a device which is coated with the polymer composition comprising a reaction product of SU-8 and at least one compound of formula I;

I

where C] -C₃o linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEf)₃, - Si(OMe)₃, -Si(OPr) , thiols, amides, propargyl or azide functional groups.

The non-limiting examples of the device in accordance with the present disclosure are micro electromechanical system (MEMS), bio-MEMS systems, nano electromechanical systems (NEMS), microfluidic structures, microfludic channels, cantilevers, waveguides or semiconductor devices.

The device of the present disclosure can be further functionalized selectively even after the manufacture.

An embodiment of the present disclosure provides a device comprising a polymer composition comprising a reaction product of SU-8 and at least one compound of formula I and a sensing molecule.

The sensing molecule is attached directly or through a linker to the device of the present disclosure.

The non-limiting examples of sensing molecule used in accordance with the present disclosure are nucleic acids, amino acids, proteins, lipids, saccharides, antigens, metabolites, or small molecules.

The nucleic acid used in accordance with the present invention can be single stranded DNA, double stranded DNA, single stranded RNA and double stranded RNA. The nucleic acid used in accordance with the present invention also includes nucleic acid analogues like the artificial nucleic acid analogs which have been designed and synthesized by chemists, and include peptide nucleic acid, morpholino- and locked nucleic acid, as well as glycol nucleic acid and threose nucleic acid.

The non-limiting examples of the amino acid compositions and proteins used in accordance with the present disclosure are peptides, polypeptides, enzymes, glycoproteins (antibodies), peptide analogues, peptide hormones, monoamines.

The non-limiting examples of the lipids used in accordance with the present disclosure are sterols, monoglycerides, diglycerides, triglycerides, phospholipids, lipid and phospholipid-derived hormones.

The non-limiting examples of saccharides used in accordance with the present disclosure are monosaccharides, disaccharides, oligosaccharides and polysaccharides.

The small molecules used in accordance with the present disclosure can be drug molecules or any other small molecules of like nature. Numerous semiconductor devices can be easily fabricated by functionalized SU-8 to behave like dielectric, semiconductor and conductor. By using functionalized SU-8 in various forms one could ensure good interface properties much like Si- Si02 (in a MOSFET), p-n junctions that is important for functional semiconductor devices.

The process of the present disclosure now allows the functionahzation of the dielectric with a thin layer of functionalized SU-8 wherein any receptor now can be chosen. Now once this covalently bound receptor with dielectric is exposed to analyte, the reaction directly happens at the dielectric surface and hence will give the signal out. Therefore, the sensing event is not necessarily restricted to pH changes. Furthermore, one can now generate a pattern of functional groups on dielectric resulting in multiple reactions on single device or use miniaturize devices with varying functionality resulting, in detection of multiple analytes in single drop test. The same can be done with SPR wherein the functionahzation of the thin gold layer can be done in similar fashion, !n order to increase binding of SU-8 with gold, we can mix A and also glycidyl ether with terminal thiol so that gold cab be bind and the epoxide with bing with functionalized SU-8.

The functional device of the present disclosure can then find applications in various fields such as Affinity Chromatography, online purification or pre- concentration of samples for lab on chip based systems and various other biomedical applications.

The process of the present disclosure enables to generate patterns or selective functionahzation of one side of microcantilevers resulting in more efficient sensing platforms. The selective functionality of parts of cantilevers can also be achieved by the process of the present disclosure.

Further, the process of the present disclosure enables the functionahzation of different channels with different functional groups to create a complete lab on a chip based system.

The process of the present disclosure provides a selectively to incorporate specific functional groups (in particular the propargyl and azide groups) in the epoxy based devices which can then be functionalized selectively after fabrication (using "CLICK" chemistry) wherein the process is simple and efficient. The post fabrication functionalisation method ("CLICK" chemistry) is also very simple and is compatible with biological functionalisation and does not required protection-deprotection strategy commonly employed in biofunctionalisation. The cured polymer composition has highly reactive functional groups which in turn have high affinity for reaction with various organic as well as functional groups and hence is capable of promoting different reactions for the further chemical functionalisation of the substrate/device. Furthermore, application based products can be obtained by carrying out the reactions by selectively protection/deprotection of the functional groups. Also, the process is versatile, compatible with CMOS fabrication and other fabrication tools. Apart from these advantages, the current process allows us to selectively functionalize domains within the prefabricated devices allowing us to design and fabricate multiple domains with different functionality within a single device ideally suited for LAB ON A CHIP type devices. It allows for different types of patterning and also for selectively functionalizing the device e.g. cantilevers can be functionalized selectively at one side. It further allows us to selectively functionalize one microchannel at a time among many as well as to do heterogeneous functionalisation of various channels of the same device e.g. one can pass reagent (different) from different channels to functionalize selectively. One can even make different functional groups within one channel. Moreover, tribological properties of the epoxy resist of the present invention can be tuned using surface functionalisation. The present method provides an ideal solution for controlling these triboloigcal properties, thus improving the wear and tear of MEMS/NEMS with moving parts and proportionally increasing their life time and also working conditions.

The polymer composition obtained by the process of the present disclosure can be functionalized with materials like proteins, antibodies, chemicals, antigens, etc after curing the polymer composition. It can be considered as first process for derivatization post polymerization. In other words, once SU 8 is made and cast into a form suitable for a given application, the epoxy resist is treated with an epoxy compound with required functional group (like amine, acid, sulphate, aldehyde etc) with which a functional group is present on the SU-8 for further derivatization. Post- polymerization derivatization offers the benefit of allowing the additional of sensing molecules in conditions which will not destroy the integrity of the sensor. For example, if protein molecules are subjected to heat, they lose their structure and often function. Post-polymerization addition of protein structures to the functionalized reaction product containing SU-8 and epoxy compound of formula I retains the integrity of the protein molecule. SCHEME-1:

Polymerization of SU-8 and general steps involved in structure preparation

SU-8 is most commonly processed with conventional near UV (350-400nm) radiation, although it may be imaged with e-beam or x-ray. i-line (365nm) is recommended. Upon exposure, cross-linking proceeds in-two-steps (1 ) formation of a strong acid during the exposure process, followed by (2) acid-initiated, thermally driven epoxy cross-linking during the post exposure bake (PEB) step. A normal process of SU-8 polymerization is: spin coat, soft bake, expose, post expose bake (PEB) and develop. Each of these steps are explained below.

Coat: SU-8 resists are designed to produce low defect coatings over a very broad range of film thickness and can be achieved by commercial spin coater.

Soft bake: After the resist has been applied to the substrate, it must be soft baked to evaporate the solvent and densify the film and it is done at 95 deg C for few seconds to minutes.

Expose: SU-8 is optimized for near UV (350-400nm) exposure. Upon exposure to this light formation of a strong acid happens (reaction of epoxide with light).

Post expose bake: Following exposure, a post expose bake (PEB) must be performed to selectively cross-l ink the exposed portions of the film. This bake can be performed either on a hot plate or in a convection oven at 60 to 100 deg C, preferably at 65 deg C or 95 deg C. Optimum cross-link density is obtained through careful adjustments of the exposure and PEB process conditions.

Develop: Solvent based developers such as ethyl lactate and diacetone alcohol are used to develop the SU-8 structures. Following development, the substrate should be rinsed briefly with isopropyl alcohol (IPA), then dried with a gentle stream of air or nitrogen for 10 min. If a hard material based SU-8 is required, then the SU-8 material is heated for few minutes at 150-200 deg C.

ht

2h

Upon exposure to light cross linking of epoxide group happens and the amine, acid, azide or aldehyde functional group gets incorporated into polymerized SU8. Using this process a simple and efficient functionalized SU8 is created and the functional group (NH2, COOH, N3 or CHO) allow reaction of these groups with biological molecules like proteins, oligomers, peptides or small molecules like antigens, pesticides, hormones etc to create MEMS, Bio-MEMS based structures.

SCHE E- 1

SCHEME-2:

Mix SU-8 and at least one compound of Formula I in an organic solvent like

toluene. Reflux the mixture for 2 to 4 hours at a temperature in the range of 30 deg C

to 300 deg C and as the reaction mixture becomes darker, continue reflux for 48

hours. The whole reaction is carried out under argon or nitrogen atmosphere. Reaction

is stopped by brining to room temperature and doing an aqueous work-up (water

washes etc). The organic phase is then separated, and concentrated on a Rota Vapor at

45 to 60 deg C under vacuum or reduced pressure till all the toluene evaporates. The

polymer composition thus obtained can be casted into required structure.

EXAMPLES

The following examples are given by way of illustration of the present invention

and should not be construed to limit the scope of present disclosure. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the claimed subject matter. Example -1;

Reaction of 4-VinyI-l -cyclohexene 1 ,2-epoxide with SU-8 and synthesis of cross- linked structure:

2 mL of liquid SU-8 is mixed with 0.2 mL of 4-VinyI- l-cyclohexene 1,2- epoxide in container for 30 min at room temperature and casted in a structure of choice. Then UV light at 350-400 nm is exposed for 5 min while heating at 65-95 deg C to initiate the cross-linking reaction and solidify the structure as per Scheme I. Now there is a polymer composition with vinyl functional group available for reaction with any compound/protein/antibody. Example-2;

Reaction of 3-amino propyl 1 ,2-epoxide with SU-8 and synthesis of cross-linked structure:

2 mL of liquid SU-8 is mixed with 0.2 mL of 3-amino propyl 1 ,2-epoxide in round bottom flask for 30 min at room temperature protected from light. The liquid is poured in a 2 cm wide circle shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the structure as per the general protocol shown in scheme-1. Allow the composition to cool to room temperature. The resulting polymer composition now has an amine group on the surface which can be further derivatized.

Example 3:

Reaction of 3-azido propyl 1 ,2-epoxide with SU-8 and synthesis of cross-linked structure

2 mL of liquid SU-8 is mixed with 0.2 mL of 3-azido propyl 1 ,2-epoxide in round bottom flask for 30 min at room temperature protected from light. The liquid is poured in a 2 cm wide circle shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the structure as per the general protocol given in Scheme-1 . Allow the composition to cool to room temperature. The resulting polymer now has an azide group on the surface which can be further derivatized.

Example 4:

Reaction of 1 ,2-epoxide 4-butaraldehyde with SU-8 and synthesis of cross-linked structure

2 mL of liquid SU-8 is mixed with 0.2 mL of 1 ,2-epoxide 4-butaraldehyde in round bottom flask for 30 min at room temperature protected from light. The liquid is poμred in a 2 cm wide circle shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the structure as per the general protocol given in scheme- 1. Allow the polymer composition to cool upto the room temperature. The resulting polymer composition now has an aldehyde group on the surface which can be further derivatized. Example-5:

Reaction of 3-amino propyl 1 ,2-epoxide with SU-8 and synthesis of cross-linked structure in the form of a channel

2 mL of liquid SU-8 is mixed with 0.2 mL of 3-amino propyl 1,2-epoxide in round bottom flask for 30 min at room temperature protected from light. The liquid is poured in a 2 cm long, 3 mm wide channel (with an inlet and outlet) shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the structure as per the general protocol given in scheme- 1 .

Allow the polymer composition to cool upto the room temperature. The polymer resulting polymer composition has an amine group on the surface which can be further derivatized.

Example 6:

2 mL of liquid SU-8 is mixed with 0.2 mL of 3-amino propyl 1 ,2-epoxide in round bottom flask for 30 min at room temperature protected from light. The liquid is poured in a 2 cm long, 3 mm wide channel (with an inlet and outlet) shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the composition as per the general protocol given in scheme- 1 . The resulting polymer composition now has an azide group on the surface.

Example 7:

2 mL of liquid SU-8 is mixed with 0.2 mL of 1 ,2-epoxide 4-butaraldehyde in round bottom flask for 30 min at room temperature protected from light. The liquid is poured in a 2 cm wide circle shaped metal casing. Then UV light at 350-400 nm is exposed for 5 min to initiate the cross-linking reaction and solidify the structure as per the general protocol given in scheme-1. Allow the polymer composition to cool to room temperature. The resulting polymer has an aldehyde group on the surface which can be further derivatized. Example 8:

Reaction of 4-Vinyl-l-cyclohexene 1 ,2-epoxide with SU-8 and synthesis of cross- linked structure:

2 mL of liquid SU-8 is mixed with 0.2 mL of 4-Vinyl- l -cyclohexene 1 ,2- epoxide and toluene in a container for 30 min at room temperature. Then the mixture is refluxed at a temperature of 50 deg C to initiate the cross-linking reaction, the general protocol shown in scheme-2 is followed. Now there is a polymer composition with vinyl functional group available for reaction with any compound/protein/antibody.

Similarly, by following the protocol as shown in scheme-2 the polymer composition in accordance with the present discloser can be prepared.

Example 9:

The channel made as per example 5 was treated for 5 min with 1 mL of 0.4% glutaraldehyde in pH 5.2, 10 mM MES buffer. After washing the channel with 1 mL water, a 200 of 10 mM Neutrophil gelatinase -associated lipocalin (NGAL) protein solution is left for 2 hours. A channel coated with NGAL is ready for bioassay.

Example 10:

The channel made as per example 5 was treated for 5 min with 1 mL of 0.4% glutaraldehyde in pH 5.2, 10 mM MES buffer. After washing the channel with 1 mL water, a 200 of 10 mM NGAL antibody solution is left in contact with the channel for 2 hours. A channel coated with NGAL antibody is ready for bioassay.

Example 11:

The channel made as per example 10 was treated for 5 min with 200 μί, of 10 mM NGAL protein solution. A channel coated with NGAL antibody and NGAL protein is ready for bioassay.

Example 12:

The channel made as per example 5 was treated for 5 min with 1 ttiL of 0.4% gl Paraldehyde in pH 5.2, 10 mM MES buffer. After washing the channel with 1 mL water, a 200 of 10 pM of probe NH2-ACGGTTTCTGGAGG is left in contact with it for 2 hours. A channel coated with nucleotide primer is ready for bioassay.

Example 13:

The channel made as per example 12 was treated for 50 min with 200 μί_^ of 10 pM of probe complementary to the sequence NH2-ACGGTTTCTGGAGG. After washing with 3 mL of deionized water, 50 μL· elution buffer containing 10 mM Tris and 1 mM EDTA at 95 deg C was added to selectively isolate the complementary sequence. This example is applicable for isolating DNA/RNA from clinical samples using complementary sequence method.

Example 14:

Process for preparing heterogeneously functionalized Cantilever

A 4" Silicon wafer was cleaned by RCA before starting the process. The RCA clean is the industry standard for cleaning the contaminants from wafers. Werner Kern developed the basic procedure in 1965 while working for RCA (Radio Corporation of America). The RCA cleaning procedure has the following steps.

The first step was performed with a 1 : 1 :5 solution of NH₄OH (ammonium hydroxide) + H₂0₂ (hydrogen peroxide) + H₂0 (water) at 75 or 80 °C typically for 10 minutes. This treatment resulted in the formation of a thin silicon dioxide layer (about 10 Angstrom) on the silicon surface, along with a certain degree of metallic contamination (notably Iron) that was removed in subsequent steps. This was followed by transferring the wafers into a De-ionized (DI) water bath.

The second step was a short immersion in a 1 :50 solution of HF + H₂0 at 25 °C, in order to remove the thin oxide layer and some fraction of ionic contaminants. The third and last step was performed with a 1 : 1 :6 solution of HC1 + H₂0₂ + H₂0 at 75 or 80 °C. This treatment removed the remaining traces of metallic (ionic) contaminants. This was followed by one more HF dip and then wafers rinsed in DI water three times and taken out, and dried in the laminar flow bench using nitrogen jet.

The silicon wafer after RCA cleaning was subjected to wet oxidation at 1050°C for 1.5 hrs to get a 500 nm oxide layer on the surface. This layer acts as a sacrificial layer and is etched in the end to release the devices.

A dehydration bake of the wafer was carried out on a hot plate, at 120°C for 5 minutes. Then 4 ml of polymer composition of the present disclosure was spin coated on the wafer at a spread cycle of 500 rpm for 10 sec, followed by spinning at 3000 rpm for 30 sec to obtain a 1 .5μ thick layer. Allow the polymer composition of the present disclosure to settle to a level for 15-30 min before beginning the soft bake. The film was then baked at 70°C for 3 min and then at 90°C for 7 min. The temperature is ramped down under the glass transition temperature between 60 deg C and 50 deg C, the ramping allows the polymer molecules to re-crystallize in a stress-free way. It is exposed to an UV dose of 62 mJ/cm² and baked again with the same baking parameters as that of pre-exposure bake.

The mask used for the process can be designed to get different patterns; the different patterns which can be obtained by this process are as shown in figure 3.

Post bake temperature of one minute at 95 degree C was given. The post baked sample was developed in SU-8 developer (PGMEA) and rinsed with Isopropyl Alcohol (IPA) and dried with nitrogen gun. Next a thin layer Polymer composition of present disclosure was coated on top of the functional ized cured layer and then soft baked and cured without mask and developed.

The last step of the process is to prepare an anchor, another thick layer of polymer composition of the present disclosure was spincoated, soft baked, exposed to U V with a different mask and developed. A hard bake at 130 degree C also was given finally. (The spin cycle consisted of two spread cycles (300 rpm for 5 sec and 500 rpm for 10 sec), a spin cycle (2200 rpm for 30 sec) and finally a slow spin cycle (300 rpm for 8 sec). It is baked at 65 deg C for 15 min and at 85 deg C for 70 min and then exposed to a U V dose of 250 mJ/cm². The cantilevers were released by etching the sacrificial layer. This was done by putting them in Buffered oxide etch (BOE 5: 1). Released dies were washed in DI water and IPA.

The process flow for obtaining heterogeneously functional ized Cantilever is shown in figure 1.

Example 15:

Process for obtaining surface patterning of Thin Films:

A regular glass slide (1" x 1") was cleaned thoroughly using De-ionized (DI) water, acetone, Isopropyl Alcohol (IPA) followed by sonication in DI water. It was then further cleaned by Piranha solution followed by DI water. Then 4 ml of polymer composition of the present disclosure was spin coated on the wafer at a spread cycle of 500 rpm for 10 sec, followed by spinning at 3000 rpm for 30 sec to obtain a 1.5μ thick layer. Then allow the polymer composition of the present disclosure to get settled to a level for 15-30 min before beginning the soft bake. The film was then baked at 70 deg C for 3 min and then at 90 deg C for 7 min. The temperature is ramped down under the glass transition temperature between 60 deg C and 50 deg C the ramping allows the polymer molecules to re-crystallize in a stress-free way. It is then exposed to an UV dose of 62 mJ/cm² through an appropriate mask and baked again with the same baking parameters as that of pre-exposure bake

The mask used for the process can be designed to get different patterns as shown in figure 3.

Post bake temperature of one minute at 95 degree C was given. The post baked thin film was developed in SU 8 developer (PGMEA) and rinsed with IPA and dried with nitrogen gun to obtain the required surface patterns.

The whole process flow for obtaining various patterns on thin films is shown in figure 2.

Example 16:

Functionalization of the thin films after the device formation:

Once the devices (thin films, cantilevers, microfluidic channels or waveguides etc.) with required surface patterning are formed, the next step is to further functionalize it with appropriate chemical or biological species. Herein the Glycidyl Azide (compound of formula I) was used along with SU-8 for surface functionlization. The surface patterning of the glycidyl azide was confirmed by observing a strong peak at 2200 cm^"1 in Grazing Angle FTIR spectroscopy. This device was then treated with propargyl bromide in order to convert the azide groups to bromide groups.

This was achieved as follows: The azide functioanlized devices were incubated with 0.5 mmols of propargyl bromides in 10 mL DMSO, followed by addition of 0.058 g (0.29mmol) of sodium ascorbate in 1.5mL water and a solution of 0.024g (0.096mmol) of CuS0₄ in lmL water to the incubating mixture. The devices were incubated at room temperature for 24 hours and the progress of the conversion of azide group to bromide was followed by the disappearing of the azide peak at 2200 cm^"1 in Grazing Angle FT1R spectroscopy. Finally the devices were cleaned thoroughly with DI water and dried in air.

Although the subject matter has been described in considerable detail with reference to certain preferred embodiments thereof, other embodiments are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment contained therein.

Claims

We Claim:

1. A process for preparation of a polymer composition comprising:

blending SU-8 and at least one compound of formula I to obtain a reaction mixture; and

curing the reaction mixture to obtain the polymer composition;

I

The process as claimed in claim 1 , wherein the curing of the reaction mixture is done by heating the reaction mixture at a temperature in the range of 30 deg C to 300 deg C or by photolytic treatment of the reaction mixture by a light having wavelength in the range of 200 nm to 800 nm or by both.

The process as claimed in claim 1 , wherein the curing is carried out for a time period in the range of 1 min to 48 hours, preferably 2 to 10 hours.

The process as claimed in claim 1, wherein the process is carried out under inert atmosphere, preferably under argon or nitrogen atmosphere.

The process as claimed in claim 1 , wherein the reaction mixture is obtained by blending an epoxy resist, at least one compound of formula I and an organic solvent.

The process as claimed in claim 5, wherein the organic solvent is selected from gamma-butyrolactone, cyclopentanone, methyl butyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, ethyl lactate, diacetone alcohol, isopropyl alcohol, toluene, benzene, xylene, ethanol or methanol, acetone, ethyl acetate, chloroform, carbon tetrachloride, dichloromethane, DMF, DMSO, preferably gamma- butyrolactone.

7. A polymer composition comprising:

a reaction product of SU-8 and at least one compound of formula I

I

wherein X is selected from C1 -C30 linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, , ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

where C1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)3, - Si(OMe)3, -Si(OPr)3, thiols, amides, propargyl or azide functional groups.

8. A process for manufacturing a device comprising:

fabricating a device with polymer composition comprising a reaction product of SU-8 and at least one compound of formula I to obtain the fabricated device;

I wherein X is selected from C1-C30 linear or branched alkyl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides; and

where C1 -C30 linear or branched alkyl, aryl, or heteroaryl are each independently optionally substituted by a group selected from amines, carboxylic acids, alcohols, ethers, sulfonic acids, -Si(OEt)3, -Si(OMe)3, -Si(OPr)3, thiols, amides, propargyl or azide functional groups.

9. The process as claimed in claim 8, wherein the fabricating of device is done by coating the device with the polymer composition to obtain the device.

10. The process as claimed in claim 8, wherein the fabricating of device is done by making the device with the polymer composition to obtain the device.

1 1 . The process as claimed in claim 8, wherein the device is selected from a micro electromechanical system (MEMS), bio-MEMS systems, nano electromechanical systems (NEMS), microfluidic, cantilevers, waveguides or semiconductor devices.

12. A device comprising:

a polymer composition comprising a reaction product of SU-8 and at least one compound of formula I;

I

wherein X is selected from C| -C₃o linear or branched alkyl, aryl, heteroaryl, or a functional group selected from amines, carboxylic acids, esters, urethanes, , ethers, sulfonic acids, thiols, amides, allyl, propargyl or azides;

13. The device as claimed in claim 12, wherein the device is made up of the polymer composition comprising a reaction product of SU-8 and at least one compound of formula I.

14. The device as claimed in claim 12, wherein the device is coated with the polymer composition comprising a reaction product of SU-8 and at least one compound of formula I.

15. The device as claimed in claim 12, wherein the device is selected from a micro electromechanical system (MEMS), bio-MEMS systems, nano electromechanical systems (NEMS), microfluidic structure, microfludic channel, cantilevers, waveguides or semiconductor devices.

16. The device as claimed in claim 12, further comprising a sensing molecule selected from nucleic acids, amino acids, proteins, lipids, saccharides, antigens, metabolites, or small molecules.

17. The device as claimed in claim 16, wherein the sensing molecule is attached directly or through a linker to the device.