Engagement Examples
Rapid Prototyping of a Superconducting Quantum Device Package
Professor Kevin O’Brien and his Quantum Coherent Electronics Group utilize the Rodgers RLE Lab to develop better high-frequency microwave packaging for superconducting quantum devices. Jennifer Wang is targeting two performance ranges in the work shown here: 1) Mode free operation below 20 GHz for qubit-frequency operation, and 2) Mode free operation in the K band (18 – 27 GHz) for the Project 8 Experiment. Their design goals include modularity, custom chip and via placement, and compensation structures to improve wirebond impedance matching. Jennifer and her colleagues use the LPKF Protolaser U4 to precisely structure copper on Rogers laminates, to drill 300 um diameter vias, and to precisely structure solder masks so that the launch of the RF connector is properly aligned to the copper pad on the board. They utilize sanding, polishing and lapping supplies to provide a copper finish that will accept an Al wire bond. Finally, they use solder paste dispensing and reflow oven equipment to complete the PCB before wire-bonding elsewhere.
The PCBs are placed in precision-machined low-oxygen copper package bodies, gold-plated in the Rodgers RLE Lab to provide an inert finish. Using packages designed for devices that typically operate from 4 to 12 GHz, they have cryo tested packages designed for qubits as well as for Josephson traveling wave parametric amplifier chips with larger form factors (5×40 mm instead of 5×5 mm). These packages feature return losses of less than -20 dB below 15 GHz at room temperature. For higher-frequency K band devices, metal cleaning and plating equipment provided by the Rodgers RLE Lab is used to plate the through-hole vias. They have also extended the approach to multi-port packages as shown by the 8-port device featured in the picture gallery here. If you’re interested in learning more about this packaging approach, then either contact Professor O’Brien or drop by the Rodgers lab and Dr. Nagle will be glad to introduce you.
Contributions of peripheral organ signaling to brain function and behavior
To better understand gut–brain communication, researchers Atharva Sahasrabudhe and Rajib Mondal, working with Professor Polina Anikeeva in the Bioelectronics Group, are using the Rodgers lab to prototype key portions of novel implantable electronics and neural probes. They utilize the LPKF Protolaser U4 to structure 9 um copper on 25 um polymide into highly conformable, stretchable, and implantable electronics. They use the Stratasys J5 Medijet to produce molds for encapsulating their implantable devices in protective elastomer. They also utilize Rodgers CAD workstations and inspection equipment to rapidliy iterate new electronics designs and to evaluate the quality of their devices once fabricated.
Devices being developed by Atharva Sahasrabudhe can reside in the intestinal lumen, whereas devices developed by Rajib Mondal are for wrapping on the entire surface of the stomach. The goal for both projects is to use this technology for developing fundamental understanding of the neural circuits of metabolism and then hack them to treat obesity and addiction.
Equipment support through Yankee ingenuity
Inside an M Squared SolsTiS titanium sapphire laser tuning cavity, a piezo motor is actuated to rotate the birefringent filter for a rough wavelength selection. The software control page reported motor referencing failure. The M Squared control box output voltage sequences appeared to be fine when disconnected from the piezo motor and measured with an oscilloscope. But when connected to the piezo motor the output appeared to be overloaded by the piezoelectric capacitance.
With help from Rodgers, Chao Li and Yin Min Goh, from the Quantum Photonics & AI Group led by Professor Dirk Englund, simulated, designed, and fabricated a booster board containing four, tunable voltage followers with adequate output impedance to drive the approximately 500 uF piezo motor input capacitance. An external vendor quoted $18k for repairs. Using Rodgers RLE Laboratory tools and expertise, Chao and Yin Min arrived at a solution more quickly and at marginal expense.
