A durable power of attorney is a power of attorney by which a principal designates another agent in writing, and the writing contains the words: "This power of attorney shall not be affected by subsequent disability or incapacity of the principal," or "This power of attorney shall become effective upon the disability or incapacity of the principal," or similar words showing the intent of the principal that the authority conferred shall be exercisable notwithstanding the principal's subsequent disability or incapacity.
12 Del. C. § 4901