Ex Parte Srinivasan et al

Patent Trial and Appeal BoardJun 9, 2014

12692954 (P.T.A.B. Jun. 9, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________ Ex parte VIJAY SRINIVASAN, MICHAEL G. POLLACK, ARJUN SUDARSAN, and ZHISHAN HUA ____________ Appeal 2012-011407 Application 12/692,954 Technology Center 1700 ____________ Before BRADLEY R. GARRIS, PETER F. KRATZ, and BEVERLY A. FRANKLIN, Administrative Patent Judges. GARRIS, Administrative Patent Judge. DECISION ON APPEAL Pursuant to 35 U.S.C. § 134, Appellants appeal from the Examiner's rejection under 35 U.S.C. § 103(a) of claims 34, 35, 38, 40, 43-55, 57-64, and 66-86 as unpatentable over Pamula (US 2007/0242111 A1, published Oct. 18, 2007) in view of Satoh (“On-Chip Microfluidic Transport and Mixing Using Electrowetting and Incorporation of Sensing Functions”, 77 ANALYTICAL CHEMISTRY, 6857-6863 (2005)) and Zhao (“Micro air bubble Manipulation by electrowetting on dielectric (EWOD):transporting, splitting, merging and eliminating of bubbles”, 7 LAB ON A CHIP, 273-280 (2007)) or Boyd (“Chemical Separations by Bubble-Assisted Interphase Appeal 2012-011407 Application 12/692,954 2 Mass-Transfer”, 80 ANALYTICAL CHEMISTRY, 2452-2456 (2008)). We have jurisdiction under 35 U.S.C. § 6. We REVERSE. Appellants claim a method of forming a bubble in a droplet actuator which comprises: providing a droplet actuator 100 comprising substrates 110, 112 configured to form a droplet operations gap 114 and a physical or chemical feature 120, 122 (e.g., recesses) provided at a predetermined locus within or exposed to the droplet operations gap and configured to retain a bubble 126 in position within the droplet operations gap; and dispensing an oil filler fluid 124 into the droplet operations gap to form a gaseous bubble 126 at the physical or chemical feature (independent claim 34, Fig. 1). Appellants also claim a similar method of providing a droplet actuator having a physical or chemical feature configured to retain a bubble in position within the droplet operations gap of the droplet actuator (independent claim 35). A copy of representative claim 34, taken from the Claims Appendix of the Appeal Brief, appears below. 34. A method of forming a bubble in a droplet actuator, the method Appeal 2012-011407 Application 12/692,954 3 comprising: (a) providing a droplet actuator comprising: (i) one or more substrates configured to form a droplet operations gap, the one or more substrates comprising electrodes arranged for conducting droplet operations in the droplet operations gap; and (ii) a physical or chemical feature provided at a predetermined locus within or exposed to the droplet operations gap and configured to retain a bubble in position within the droplet operations gap; and (b) dispensing an oil filler fluid, which fluid is sufficiently immiscible with a droplet phase to render the droplet phase subject to electrode- mediated droplet operations, into the droplet operations gap at a rate and volume sufficient to fill the fluid reservoir and to form a gaseous bubble at the physical or chemical feature, wherein the gaseous bubble is at least partially surrounded by the oil filler fluid. The Examiner finds that Pamula discloses methods of the type claimed (Ans. 4-5) which utilize a hybrid system wherein “droplet manipulation [in the droplet actuator] is performed both in air and in an immiscible liquid filler fluid such as oil” (id. at 5) but that “Pamula does not teach a physical or chemical feature within the droplet operations gap to retain a bubble or pocket of air or gas to create the hybrid system” (id. at 5- 6). The Examiner finds that Satoh and Zhao or Boyd supply this deficiency of Pamula (id. at 6-8) and reaches the following obviousness conclusion: Appeal 2012-011407 Application 12/692,954 4 It would have been obvious to one of ordinary skill in the art at the time the invention was made to incorporate structures as taught by Satoh ʼ05 to form gas bubbles that at least confine the filler liquid of Pamula to designated areas of the hybrid Pamula systems or to the areas in which droplet operations are occurring in the Pamula methods as taught by Satoh ʼ05 for the purpose of limiting the fluid in the operation gap to defined areas of fluid transport as taught by Satoh ʼ05 since it facilitates fluid transport as taught by Satoh ʼ05. It would have been obvious to one of ordinary skill in the art at the time the invention was made to incorporate gas bubbles/air gaps into the Pamula methods for their use to perform separations, contain and/or transport components used in a diagnostic process or other purposes as taught by Zhao or Boyd because of the ability to provide these capabilities on a micro scale and their usefulness in diagnostic assay at this scale as shown by Zhao and Boyd. (Id. at 8). Appellants argue that Pamula contains no teaching or suggestion of a method wherein a bubble is retained in position within a droplet operations gap as required by the independent claims (Br. 5-6). Appellants further argue that the Examiner's proposal “to incorporate structures as taught by Satoh ʼ05 to form gas bubbles that at least confine the filler liquid of Pamula to designated areas . . . as taught by Satoh ʼ05 for the purpose of limiting the fluid in the operation gap to defined areas of fluid transport as taught by Satoh ʼ05” (Ans. 8) would not have been suggested by Satoh and Zhao or Boyd (id. at 7-11). Appeal 2012-011407 Application 12/692,954 5 In response, the Examiner refers to paragraphs [0397], [0405] and [0428] of Pamula as providing “a clear indication that contrary to the urging of appellant Pamula does suggest a fixed region of gas or fixed bubble” (Ans. 9). According to the Examiner: Since the Pamula reference teaches a hybrid device having both gas and oil fil[l]ed regions, the Satoh ʼ05 reference clearly teaches how to do this and one of ordinary skill in the art would have found it obvious to provide the Pamula microdroplet actuator system with the physical and/or chemical feature of Satoh ʼ05 teachings to confine the oil filler as it is injected into the droplet operations gap to defined regions in the creation of the hybrid system. (Id. at ¶ bridging 10-11). We agree with Appellants that Pamula contains no teaching or suggestion of the claimed methods wherein a bubble is retained in position within a droplet operations gap. The Pamula disclosures cited by the Examiner teach using both gas and liquid in a droplet operations gap but fail to teach or suggest an arrangement of the type taught by Satoh (see, e.g., Fig. 1) wherein a liquid column is bounded on each side by a fixed air gap or bubble. The failure of Pamula to teach or suggest such an arrangement completely undermines the Examiner's conclusion that it would have been obvious “to incorporate structures as taught by Satoh ʼ05 to form gas bubbles that at least confine the filler liquid of Pamula to designated areas . . . as taught by Satoh ʼ05” (Ans. 8). Appeal 2012-011407 Application 12/692,954 6 It follows that we will not sustain the Examiner's § 103 rejection of the appealed claims. The decision of the Examiner is reversed. REVERSED lp