The Defense Advanced Research Projects Agency (DARPA) is issuing a Microsystems Exploration topic (µE) inviting submissions of innovative basic or applied research concepts in the technical domain of extreme environment electronics. This µE is issued under the Program Announcement for Microsystems Exploration, DARPA-PA-21-05. All proposals in response to the technical area(s) described herein will be submitted to DARPA-PA-21-05 and if selected, will result in an award of an Other Transaction (OT) for prototype project not to exceed $1,000,000.