BIOELECTRONICS Rahul Sarpeshkar Associate Professor Research Lab of Electronics Electrical Engineering and Computer Science Bio-inspired Electronics: Electronics inspired by biology. Biomedical Electronics: Ultra-low-power electronics for medical applications CBA NSF talk. 10/12/06

Dynamic Range120 dB at input Power Dissipation~14  W (Estimated) Power Supply Voltage~150 mV Volume~35mm x 1cm x 1 cm Det. Thr. At 3 kHz0.05 Angstroms at eardrum Frequency Range20 Hz – 20 kHz (in babies?) Outlet Taps~35,000 Filter Computations>1 GFLOPS Phase locking threshold~5 kHz Information is reported with enough fidelity so that the auditory system has thresholds for ITD discrimination at ~10  s Freq. discrimination at2 Hz (at 1kHz) Loudness discrimination~1 dB BIOLOGICAL COCHLEAR NUMBERS

Transmission Line Analogy: Fluid is an Inductor, Membrane Stiffness is a Capacitor

ANALOG VLSI AND BIOLOGICAL SYSTEMS LAB The RF cochlea  UMC 0.13µm CMOS process HF (5GHz) LF (250MHz) Transformer Single stageBias & programming

Spiking-Neuron-Inspired Analog-to-Digital Converter At 0.12pJ/quantization level, a version of this A-to-D may be the most energy-efficient A-to-D ever reported thus far. It is the first time-based A-to-D converter whose conversion time scales linearly with bit precision.

An Ultra-Low-Power Analog Bionic Ear Processor The Bionic Ear (Cochlear Implant) The 251  W 16-channel Programmable Processor Performance Summary 1.20x power improvement over best design today 2. Better or comparable performance in 1.5  m technology today than A-D-then-DSP solution at the end of Moore’s law in an advanced nanometer technology. 3.First test with a deaf patient was successful, and she understood speech with it. Block Diagram of Processor 1.Microphone 2.Cable 3.Speech Processor 4.Coil 5.Implanted Receiver 6.Electrodes 7.Auditory Nerve

CURING PARALYSIS: ELECTRONICS THAT DECODES THOUGHT

An Analog Architecture for Neural Recording, Decoding, and Learning Adaptive 7  W neural amplifier SPICE simulation of performance with real monkey data Allows 1kbs -1 instead of 24Mbs -1 data bandwidth across the skull

PRINCIPLES FOR ENERGY-EFFICIENT DESIGN IN BIOLOGY AND ELECTRONICS 1.Special-Purpose Architectures 2.Exploit analog basis functions for efficient preprocessing before digitization or signal-to-symbol conversion 3.Slow-and-Parallel 4.Exponential computing primitives (high g m /I ratio in transistor) 5. Balance Computation and Communication Costs 6. Adaptive Architectures with Learning