Nanoscale Self-Assembly A Computational View

1. Nanoscale Self-AssemblyA Computational View Philip Kuekes Quantum Science Research HP Labs

2. What’s Cooking?Everybody likes Recipes

3. Two Challenges for Nanoelectronics • Invent a new switching device • Develop a new fabrication process • Examine Architecture First

4. HPL Teramacmulti-architecture computer • 106 gates operating at 106 cycle/sec • 100 times workstation performance • Largest defect-tolerant computer ever built • 220,000 (3%) defective components

5. Defect Theology • Original Sin • Redemption Through Good Works • Guilt by Association

6. Redundant Testing PASS PASS PASS FAIL PASS PASS FAIL PASS PASS PASS

7. Defect Tolerance for Free • CMOS Technology –Configuration bit >20 x wire crossing area • Molecular Technology –Configuration bit smaller than wire crossing

8. Memory 0 Switch Teramac crossbar Teramac Crossbar Architecture

9. 4PF6- O O O O O O O O O O O O O O O O + + N N N N N N + + CH2OH Rotaxane Molecular Switch -Prof. Fraser Stoddart, UCLA C.P. Collier, E.W. Wong et al.

10. 10 Ti 5 0 Current (mA) -5 Pt -10 -1.0 0.0 -2.0 1.0 Voltage (V) Experimental Realization of aMolecular-Tunneling Switch Device = Molecule + Electrodes

11. Moletronics Architecture • Wires • Memories • Logic • Integrated Circuits

12. Crossbar at 17 nm half-pitch width • Smallest virus 30-42 nm • hepatitis B

13. Parallel ErSi2 wires grown by self-assembly 2 nm width with a nine nanometer separation

14. a b c d e f Logic Array Design U V W X Y Z Y = (U AND V) OR(W AND X) Z = V+ C = V-

15. RESET SET 1 SET 2 ENABLE RESTORE & INVERT Clock / control C1C2 SW1 SW2 E D Data input Q Data out MOLECULAR SWITCH LATCH: EXPT DATA

16. Expt: Latch works! Signal restoration Inversion, if desired >100mV operating margin No nanoscale transistor! J. Appl. Phys. Feb 1, 2005

17. Random Demultiplexer

18. ‘C20’ O C C H H O Pt 3 TiAl TiAl Pt Al Ti V LB Pt SiO2 Si 2003 NAND HP crossbar switches & circuits 16 k 1 k 2005 (ITRS 2018) 64 2004 1 2002

19. How does a Molecular Computer Grow Up? Conventional Computer Teacher Low Bandwidth Link Initially Stupid Molecular Student

20. I Get By With A Little HelpFrom My Friends Tutors Doctors

21. Complexity Self Assembly & Thermodynamics Arbitrary Graphs

22. Tradeoffs Cost of doing the chemistry Cost of doing the computing

23. The Pure and the Grubby

24. The Math - Expanders- Cayley Graphs- Ramanujan Graphs

26. Today • Physical Scientists can only do very simple self-assembly • Mathematicians can create interesting complex structures with very simple generators

27. The new capability • Combine the simple physical processes with the mathematical constructions • Nanoscale self-assembled systems with enough complexity to do useful computation.

28. The Physics • Self-Assembled DNA Nanostructures • Self-Assembled Surface Chemistry • Viral Self-Assembly • Molecular Electronic Circuit Assembly • DNA-linked Nano-particle Structures

29. The MathAdvantages of Simple Construction • amenable to self-assembly • short explicit description • highly-connected • sparse

30. Physical StructuresNot Just Abstract Graphs • defect-tolerance • efficiently embedded in three-dimensional space • relatively short edge-lengths.

31. Algorithmic Manufacturing • Local rules • Global structure

32. Feedback and the Way Forward • Computer Code • Biology • Chemistry, Physics, Materials Science

33. Feedback and the Way Forward • Computer Code • Biology • Chemistry, Physics, Materials Science • Reaction Diffusion

34. Stealing from Biology

35. DNA and Proteinsversus Cells Logic Design as Geometry Spatial Structure Controlled diffusion Compartments as wires

36. Organelles

37. Garbage Collection Ubiquitin Apoptosis Mass transport

38. The Best of Both Worlds Self-assembly Adaptive External Programming Self-disassembly

39. Tradeoffs Cost of doing the chemistry Cost of doing the computing