Drupal development

Drupal, a free open-source content-management system (CMS), is one of the world's most popular CMS platforms and used by sites including WhiteHouse.gov. I have developed and currently maintain a number of Drupal projects and web sites (see below). Some of my projects are hosted on drupal.org.

I am currently a technical architect at Acquia, responsible for the technical delivery of many Alex top-10,000 sites.


Human-in-the-Loop Control of a Bipedal Robot with Variable Levels of Autonomy

NASA's Robonaut 2 (R2) is a highly capable dexterous humanoid robot; taking full advantage of this capability and complexity, however, requires an intuitive and efficient control system. I augmented the standard mouse and keyboard teleoperative interface with a haptic device that allows for more intuitive and efficient control. This interface takes advantage of available sensor data and R2's on-board motion planning capabilities to assist the operator in performing tasks safely and efficiently. I also designed a software and hardware interface that integrates pressure data from a tactile sensing array into ROS.

Improved touch sensing for the Haptic Creature

The haptic creature is a fur-covered robot designed to assist children with emotional and developmental difficulties. It can react to human input, such as stroking or poking, by purring, breathing, and raising its ears. I designed, implemented, and analyzed a new touch-sensing suite based on quantum tunneling composites.


Powell, D, O'Malley, MK. 2012. The Task-Dependent Efficacy of Shared-Control Haptic Guidance Paradigms. IEEE Transactions on Haptics.

Powell, D, O'Malley, MK. 2011. Efficacy of Shared-Control Guidance Paradigms for Robot-Mediated Training. IEEE World Haptics Conference.