2015 ANNUAL REPORT PRAKASH LAB

Indian Government Supports Distribution of Foldscopes The team of Professor Manu Prakash, his student Jim Cybulski, postdoc Tom Hata, project manager Marie Herring and assistant Christine Kurihara traveled to Delhi in December to hold workshops on the lab’s ‘$.50 microscope,’ the Foldscope. Pictured above was one such workshop at a school just outside Delhi. To date their have been more than 50,000 Foldscopes distributed to over 135 countries. Read more about it at http://foldscope.com or see some of the images that have been captured at http://microcosmos.foldscope.com. This year we hope to distribute many more with the help of our partners and people like you.

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DROPLETS HOW THEY BEHAVE

MICROFLUIDICS MADE SIMPLE

FOLDSCOPE 50,000 AND COUNTING

MOSQUITOES AND THEIR DETECTION

The Department of Biotechnology

funded workshops in India to

propagate use of Foldscopes

PRAKASH LAB

2015 ANNUAL REPORT PRAKASH LAB

SURFACE TENSION DOMINATES INSECT FLIGHT ON FLUID -Mukundarajan, Haripriya, Bardon, T., Prakash, Manu

Flight on the 2D air–water interface, with body weight supported by surface tension, is a unique locomotion strategy well adapted for the environmental niche on the surface of water. Although previously described in aquatic insects like stoneflies, the biomechanics of interfacial flight has never been analyzed. We reported in the Journal of Experimental Biology on interfacial flight as an adapted behavior in waterlily beetles (Galerucella nymphaeae) which are also dexterous airborne fliers. We presented the first quantitative biomechanical model of interfacial

flight in insects, uncovering an intricate interplay of capillary, aerodynamic and neuromuscular forces. We showed that waterlily beetles use their tarsal claws to attach themselves to the interface, via a fluid contact line pinned at the claw. We investigated the kinematics of interfacial flight trajectories using high-speed imaging and constructed a mathematical model describing the flight dynamics. Our results showed that non-linear surface tension forces make interfacial flight energetically expensive compared with airborne flight at the relatively high speeds characteristic of waterlily beetles, and cause chaotic dynamics to arise naturally in these regimes. We identified the crucial roles of capillary–gravity wave drag and oscillatory surface tension forces which dominate interfacial flight, showing that the air–water interface presents a radically modified force landscape for flapping wing flight compared with air.

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Papers Published from the Lab

Surface tension dominates insect flight on fluid interfaces. Journal of Experimental Biology

Punch Card Programmable Microfluidics PLoS ONE

Sychronous Universal Droplet Logic and Control Nature Physics

2015 ANNUAL REPORT PRAKASH LAB

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-Korir, George, Prakash, Manu

Small volume fluid handling in single and multiphase microfluidics provides a promising strategy for efficient bio-chemical assays, low-cost point-of-care diagnostics and new approaches to scientific discoveries. However multiple barriers exist towards low-cost field deployment of programmable microfluidics. Incorporating multiple pumps, mixers and discrete valve based control of nanoliter fluids and droplets in an integrated, programmable manner without additional required external components has remained elusive. Combining the idea of punch card programming with arbitrary fluid control, here we describe a self-contained, hand-crank powered, multiplex and robust programmable microfluidic platform. normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word “PUNCHCARD MICROFLUIDICS” using the droplet generator. A paper tape encodes information

as a series of punched holes. A mechanical reader/actuator reads these paper tapes and correspondingly executes operations onto a microfluidic chip coupled to the platform in a plug-and-play fashion. Enabled by the complexity of codes that can be represented by a series of holes in punched paper tapes, we demonstrate independent control of 15 on-chip pumps with enhanced mixing, normally-closed valves and a novel on-demand impact-based droplet generator. We demonstrate robustness of operation by encoding a string of characters representing the word “PUNCHCARD MICROFLUIDICS” using the droplet generator. Multiplexing is demonstrated by implementing an example colorimetric water quality assays for pH, ammonia, nitrite and nitrate content in different water samples. With its portable and robust design, low cost and ease-of-use, we envision punch card programmable microfluidics will bring complex control of microfluidic chips into field-based applications in low-resource settings and in the hands of children around the world.

PUNCH CARD PROGRAMMABLE MICROFLUIDICS

2015 ANNUAL REPORT PRAKASH LAB

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SYNCHRONOUS UNIVERSAL DROPLET LOGIC & CONTROL -Katsikis, Georgios, Cybulski, James, Prakash, Manu

Droplets are versatile digital materials; they can be produced at high throughput, perform chemical reactions as miniature beakers and carry biological entities. Droplets have been manipulated with electric, optical, acoustic and magnetic forces, but all these methods

use serial controls to address individual droplets. An alternative is algorithmic manipulation based on logic operations that automatically compute where droplets are stored or directed, thereby enabling parallel control. However, logic previously

implemented in low-Reynolds-number droplet hydrodynamics is asynchronous and thus prone to errors that prevent scaling up the complexity of logic operations. Here we present a platform for error-free physical computation via synchronous universal logic. Our

platform uses a rotating magnetic field that enables parallel manipulation of arbitrary numbers of ferrofluid droplets on permalloy tracks. Through the coupling of magnetic and hydrodynamic interaction forces between droplets, we developed AND, OR, XOR, NOT

and NAND logic gates, fanouts, a full adder, a flip-flop and a finite-state machine. Our platform enables large-scale integration of droplet logic, analogous to the scaling seen in digital electronics, and opens new avenues in mesoscale material processing.

2015 ANNUAL REPORT PRAKASH LAB

Awards for the lab

Talks Given

Award Presenter Award Award Recipient

NIH Director New Innovator Award Manu Prakash

National Geographic Emerging Explorer Manu Prakash

MECON 2015 Best Poster Yorgos Katsikis

Nikon Small World Imaging Honorable Mention Haripriya Mukundarajan

DFD Video Contest First place Saad Bhamla

Stanford University PhD Degree Jim Cybulski

White House Mention in Memorandum on Citizen Science Manu Prakash

Bio-X Bio-X Fellowship Matt Bull, Deepak Krishnamurthy

NSF Fellowship Matt Bull

NSF Honorable Mention Laurel Kroo

Popular Science Finalist, Invention Awards George Korir

Type Event Location

Invited Talk NIMH Directors Innovation Speaker Series Washington, DC

Invited Talk AAAS Annual Meeting San Jose, CA

Invited Talk UNESCO International Year of the Light Paris, France

Invited Talk National Geographic Explorers Week Washington, DC

Invited Panelist Global Leaders Conference, IIT San Jose, CA

Keynote Speaker 160th Anniversary Department of Cell & Developmental Biology

University of Michigan

Invited Demonstration StartupKonnect, US + Government of India San Jose, CA

Invited Workshop Host Department of Biotechnology, Indian Government Delhi, India

Invited Talk Biophysics Retreat Washington, DC

Invited Talk EvoDevo Pan America Meeting Berkeley, CA

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2015 ANNUAL REPORT PRAKASH LAB

Press about the Lab

Patents Submitted

Date Title Source

March 2, 2016 Curiosity leads Stanford bioengineering to discover the inner workings of a novel mode of insect flight

Stanford News

August 24 A Smartphone Microscope Gets the Ultimate Test: The Amazon

Wired Magazine

August 31 This 50-Cent Paper Microscope Could 'Democratize Science'

The World Post

September 1 You too can build a computer that works drop by drop

The New York Times

September 1 The $1 Pocket Microscope The Atlantic

October 6 DBT partners with US-based Prakash Lab to procure low-cost microscope

Business Standard

Winter Tackling Global Poverty One Note at a Time Harvey Mudd College Magazine

December 21& 28 Through the Looking Glass - Can a cheap, portable microscope revolutionize global health?

The New Yorker

Date Title Inventors

11/17/2015 Paperfuge: An integrated paper-based centrifugation and microfluidics platform for low-cost diagnostics.

Manu Prakash, Saad Bhamla, Jim Cybulski

8/13/2015 Low cost scanning electron microscope Fabian Pease, Jim Cybulski, Manu Prakash

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2015 ANNUAL REPORT PRAKASH LAB

From Manu Prakash

We are a curiosity driven research group working in the field of engineering and physical biology probing biological system with an engineering and physics approach. Thank you for your interest in our lab and the projects we do here. We have achieved these results with the support of donors, grants and university funding. We are reliant on these sources to run our research laboratory.

Together we can bring new knowledge to light and impact the world through significant changes to the way we think about scientific instrumentation.

Supporters

We are grateful to the organizations who have supported the work of the lab.

• Gordon & Betty Moore Foundation

• National Science Foundation

• National Institutes of Health

• Keck Foundation

• Pew Foundation

• Gates Foundation

• Woods Foundation

• Vodafone

• Department of the Army

• Stanford Spectrum

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• Government of India’s Department of Biotechnology

• Coulter Foundation

• National Geographic

• mHealth Alliance

• Anderson Scholar Program

• Terman Scholar Program

• Baxter Foundation

• Sullivan Family Fund

• Stanford Bioengineering Department

2015 ANNUAL REPORT PRAKASH LAB

Drs. Pease [l] and Prakash [r] congratulate Dr. James Cybulski on his doctoral conferrence.

Prakash Lab

443 Via Ortega, Rm 064

Stanford University

Stanford, CA 94305-4125

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